Wikipedia:Manual of Style/Dates and numbers

"WP:NUMBERS" redirects here. For the WikiProject, seeWikipedia:WikiProject Numbers.For the notability guideline, seeWikipedia:Notability (numbers).

This page guides the presentation of numbers, dates, times, measurements, currencies, coordinates, and similar items in articles. The aim is to promote clarity, cohesion, and consistency, and to make the encyclopedia easier and more intuitive to use. For numbers, dates, and similar items in Wikipedia article titles, see the"Naming conventions (numbers and dates)"guideline.

Where this manual gives options, maintain consistency within an article unless there is a good reason to do otherwise. TheArbitration Committeehas ruled that editors should not change an article from one guideline-defined style to another without a substantial reason unrelated to mere choice of style;edit-warringover optional styles is unacceptable.If discussion fails to resolve the question of which style to use in an article, defer to the style used by the first major contributor.

General notes

Quotations, titles, etc.

See also:Wikipedia:Manual of Style § Quotations

Quotations, titles of books and articles, and similar "imported" text should be faithfully reproduced, even if they use formats or units inconsistent with these guidelines or with other formats in the same article. If necessary, clarify via [bracketed interpolation], article text, or footnotes.

Non-breaking spaces

Guidance on the use ofnon-breaking spaces( "hard spaces" ) is given in some sections below, but not all situations in which hard spaces ({{nbsp}}or) or{{nowrap}}may be appropriate are described.For further information seeWikipedia:Manual of Style § Non-breaking spacesandWikipedia:Line-break handling.

Chronological items

Statements likely to become outdated

See also:Wikipedia:Manual of Style/Words to watch § Relative time references,Wikipedia:Updating information,andWikipedia:As of

Except on pages that are inherently time-sensitive and updated regularly (e.g.the "Current events" portal), terms such asnow,today,currently,present,to date,so far,soon,upcoming,ongoing,andrecentlyshould usually be avoided in favor of phrases such asduring the 2010s,since 2010,andin August 2020.Wording can usually be modified to remove the "now" perspective: notshe is the current directorbutshe became director on 1 January 2024;not2010–presentbutbeginning in 2010orsince 2010.Terms likely to go out of date includebest known for,holds the record for,etc.For current and future events, use phrases such asas of July 2024orsince the beginning of 2024to signal the time-dependence of the information; use the template{{as of}}(or{{updated}}) in conjunction. Relative-time expressions are acceptable for very long periods, such as geological epochs:Humans diverged from other primates long ago, butonly recently developed state legislatures.

Dates, months, and years

"WP:YEAR" redirects here. For WikiProject Years, seeWP:YEARS.

• These requirements do not apply to dates in quotations or titles;seeWikipedia:Manual of Style § Quotations.
• Special rules apply to citations;seeWikipedia:Citing sources § Citation style.
• See alsoWikipedia:Overview of date formatting guidelines.

Formats

Acceptable date formats

General use	Only in limited situations where brevity is helpful	Comments
2September 2001	2Sep 2001	A comma doesn't follow the year unless otherwise required by context: The 5 May 1922 meeting was cancelled. Except Jones, who left London on 5 March 1847, every delegate attended the signing.
September2, 2001	Sep2, 2001	A comma follows the year unlessother punctuation obviates it: The weather on March 12, 2005, was clear and warm. Everyone remembers July20, 1969 – when humans first landed on the Moon.
2September	2Sep	Omit year only where there is no risk of ambiguity: The 2012 London Olympics ran from 25July to 12September. January1 is New Year's Day.
September2	Sep2
No equivalent forgeneral use	2001-09-02	Useyyyy-mm-ddformat only withGregoriandates from 1583 onward.
September 2001	Sep 2001

• Dates, years, and other chronological items should be linked only when they are relevant to the subjectandlikely to be useful to a reader; this rule does not apply to articles that are explicitly on a chronological item, e.g.2002,19th century(as discussed atWikipedia:Linking § Chronological items).
• For issues related to dates in sortable tables,seeHelp:Sortable tables § Configuring the sortingandHelp:Sortable tables § Date sorting problems,or consider using{{dts|Nov 1, 2008}}.
• Phrases such asFourth of July(orJulyFourth,but notJuly4th),Cinco de Mayo,Seventh of March Speech,andSete de Setembroare proper names, to which rules for dates do not apply (A typical Fourth of July celebration includes fireworks).

Unacceptable date formats (except inexternal titles and quotes)

Unacceptable	Corrected	Comments
Sep.2	Sep 2	Do not add a full stop (period) to an abbreviated month or to theday-of-month.
9.June	9JuneorJune9
9 june june 9		Months should be capitalized.
9th June June 9th the 9th of June		Do not useordinals(1st,2nd,3rd,etc.).
09-06 06-09		Do not use these formats.
09 June June 09		Do not zero-pad day...
2007-4-15	2007-04-15	... except in all-numeric(yyyy-mm-dd) format,in which month and day are zero-padded to twodigits.
2007/04/15		Do not use separators other than hyphens.
20070415		Do not omit hyphens.
07-04-15		Do not abbreviate year.
15-04-2007 04-15-2007 2007-15-04		Do not usedd-mm-yyyy,mm-dd-yyyyoryyyy-dd-mmformats.
2007 April 15 2007 Apr 15		Do not use these formats.
7/2001 7-2001 07-2001 2001-07 2001 July July of 2001	July 2001	Do not use theseformats.
July,2001		No comma between month andyear.
3 July,2001	3July 2001
July 3 2001	July3,2001	Comma required between day andyear.
the'97 elections the97 elections	the 1997 elections	Do not abbreviate year.
Copyright MMII	Copyright 2002	Roman numeralsare not normally used fordates.
Two thousand one	2001	Years and days of the month are not normally written inwords.
the first of May May the first	1MayorMay1
June 0622	June 622	Do not zero-pad years.
June 2,015	June 2015	Do not add a comma to a four-digit year.
sold in the year 1995	sold in 1995	Write "the year" only where needed for clarity (About 200 shipsarrived inthe year 300).

Consistency

• Dates in article body textshould all use the same format:She fell ill on25 June 2005and died on28 June,notShe fell ill on25 June 2005and died onJune 28.
• Publication datesin an article's citations should all use the same format, which may be:
  • the format used in the article body text,
  • an abbreviated format from the"Acceptable date formats" table,provided the day and month elements are in the same order as in dates in the article body
  • the format expected in thecitation stylebeing used (but all-numeric date formats other thanyyyy-mm-ddmust still be avoided).
  For example, publication dates within a single article might be in one, but only one, of these formats (among others):
  • Jones, J. (20 September 2008)
  • Jones, J. (September 20, 2008)
  If an article uses a template such as{{Use mdy dates}}or{{Use dmy dates}},thenCitation Style 1and2templates automatically render dates (|date=,|access-date=,|archive-date=,etc) in the specified format, regardless of the format they are entered in. (The|cs1-dates=parameter can be used to fine-tune the generated output,seeTemplate:Use mdy dates § Auto-formatting citation template dates.)
• Access and archive datesin an article's citations should all use the same format, which may be:
  • the format used for publication dates in the article (see above);
  • the format expected in the citation style adopted in the article; or
  • yyyy-mm-dd
  For example, access/archive dates within a single article might be in one, but only one, of these formats (among others):
  • Jones, J. (September 20, 2008)... Retrieved February 5, 2009.
  • Jones, J. (20 Sep 2008)... Retrieved 5 Feb 2009.
  • Jones, J. (20 September 2008)... Retrieved 2009-02-05.
  When a citation style does not expect differing date formats, it is permissible to normalize publication dates to the article body text date format, and/or access/archive dates to either, with date consistency being preferred.

Strong national ties to a topic

For any given article, the choice of date format and the choice of national variety of English (seeWikipedia:Manual of Style § Strong national ties to a topic) are independent issues.

• Articles on topics with strong ties to a particular English-speaking country should generally use the date format most commonly used in that nation. For the United States this is (for example)July 4, 1976;for most other English-speaking countries it is4 July 1976.
• Articles related to Canada may use either format with (as always) consistency within each article. (see Retaining existing format)
• In topics where a date format that differs from the usual national one is in customary usage, that format should be used for related articles: for example, articles on the modern US military, including biographical articles related to the modern US military, should use day-before-month, in accordance with US military usage.

Retaining existing format

See also:Wikipedia:Manual of Style § Retaining existing styles

• If an article has evolved using predominantly one date format, this format should be used throughout the article, unless there are reasons for changing it based on the topic's strong ties to a particular English-speaking country, or consensus on the article's talk page.
• The date format chosen in the first major contribution in the early stages of an article (i.e., the first non-stub version) should continue to be used, unless there is reason to change it based on the topic's strong ties to a particular English-speaking country, or consensus on the article's talk page.
• Where an article has shown no clear sign of which format is used, the first person to insert a date is equivalent to "the first major contributor".

Era style

"WP:BCE" redirects here. For the copyediting guide, seeWikipedia:Basic copyediting.

• The defaultcalendar erasareAnno Domini(BCandAD) andCommon Era(BCEandCE). Either convention may be appropriate for use in Wikipedia articles depending on the article context. ApplyWikipedia:Manual of Style § Retaining existing styleswith regard to changes from one era to the other.
  • Use either the BC–AD or the BCE–CE notation consistently within the same article. Exception: do not changedirect quotations,titles, etc.
  • An article's established era style should not be changed without reasons specific to its content; seek consensus on the talk page first (applyingWikipedia:Manual of Style § Retaining existing styles) by opening a discussion under a heading using the wordera,or another similarly expressive heading, and briefly stating why the style should be changed.
  • BCE and CE or BC and AD are written in upper case, unspaced, without a full stop (period), and separated from the numeric year by a space (5BC,not5BC). It is advisable to use anon-breaking space.
  • AD appears before or after a year (AD106,106AD); BCE, CE, and BC always appearafter(106CE,3700BCE,3700BC).
  • In general, omit CE or AD, except to avoid ambiguity or awkwardness.
    • Typically, writeTheNorman Conquesttook place in 1066not1066CEorAD1066.
    • ButPlotinuslived at the end of the 3rd century AD(not simplyat the end of the 3rd century) may avoid confusion unless the era is clear from context.
    • One- and two-digit years may look more natural with an era marker (born in 2 ADorborn January 15, 22 CE,notborn in 2norJanuary 15, 22).
    • Ranges beginning in BC / BCE should specify the ending era: write450 to 200 BCEor450 BC to 200 BCor450 BCE to 200 CE,but not450 BCE to 200.(seeRanges)
• Uncalibrated (BCE) radiocarbon dates:Calibrated and uncalibrateddates can diverge widely, and some sources distinguish the two only via BCE or BC (for calibrated dates) versus bce or bc (uncalibrated). When feasible, avoid uncalibrated dates except in direct quotations, and even then ideally give the calibrated date in a footnote or square-bracketed note –[3250BCE calibrated],or at least indicate the date type –[uncalibrated].This also applies to other dating systems in which a calibration distinction is drawn.
• BP or YBP:In scientific and academic contexts, BP (Before Present) or YBP (years Before Present) are often used. (Presentin this context by convention refers to January1, 1950.) Write3000 yearsBPor3000YBPor3000years before presentbut not forms such as3000 before presentand3000 years before the present.If one of the abbreviated forms is used, link toBefore Presenton first use:The Jones artifact was dated to 4000YBP,the Smith artifact to 5000 YBP.
• Other era systemsmay be appropriate in an article. In such cases, dates should be followed by a conversion to Anno Domini or Common Era, and the first instance linked:Qasr-al-Khalifa was built in221AH(836 CE),orin 836 AD (221AH).
  • Astronomical year numberingis similar to the Common Era. There is no need to follow a year expressed with astronomical year numbering with a conversion to Common Era. The first instance of a non-positive year should still be linked:The March equinox passed into Pisces inyear−67.(The expressions−67and68BCErefer to the same year.)

Julian and Gregorian calendars

See also:Old Style and New Style dates

A date can be given in any appropriate calendar, as long as it is (at the minimum) given in theJulian calendaror theGregorian calendaror both, as described below. For example, an article on the earlyhistory of Islammay give dates in bothIslamicand Julian calendars. Where a calendar other than the Julian or Gregorian is used, the article must make this clear.

• Current events are dated using the Gregorian calendar.
• Dates of events in countries using the Gregorian calendar at that time are given in the Gregorian calendar. This includes some of theContinent of Europe from 1582,theBritish Empirefrom 14September 1752, and Russia from 14February 1918(seeAdoption of the Gregorian calendar).
• Dates before 15October 1582 (when the Gregorian calendar was first adopted in some places) are normally given in the Julian calendar.
• Dates after 4October1582 in a place where the Julian calendar was observed should be given in the Julian calendar.
• For either the Julian or Gregorian calendars, the beginning of the year should be treated as 1January even if a different start-of-year date was observed in the place being discussed.
• Dates for Roman history before 45BC are given in theRoman calendar,which was neither Julian nor Gregorian. When (rarely) the Julian equivalent is certain, it may be included.
• For dates in early Egyptian and Mesopotamian history, Julian or Gregorian equivalents are often uncertain. Follow the consensus of reliable sources, or indicate their divergence.

The dating method used should follow that used by reliable secondary sources (or if reliable sources disagree, that used most commonly, with an explanatoryfootnote). The guidance above is in line with the usage of reliable sources such asAmerican National Biography,Oxford Dictionary of National Biography,andEncyclopædia Britannica.

Where it is not obvious that a given date should be given in Julian alone or in Gregorian alone, consider giving both styles, for example by using{{OldStyleDate}}.If a date appears without being specified as Old Style or New Style, tagging that date with{{which calendar?}}will add the page toCategory:Articles containing ambiguous datesfor further attention.

If an article contains Julian calendar dates after 4 October 1582 (as in theOctober Revolution), or if a start-of-year date other than 1 January was in force in the place being discussed, or both, a footnote should be provided on the first usage, explaining the calendar usage adopted for the article. The calendar usage should be compatible with this guideline.

Ranges

See also:Wikipedia:Manual of Style § Number ranges

"MOS:DIED" redirects here. For euphemisms for "died", seeWikipedia:Manual of Style/Words to watch § Euphemisms.

• A simpleyear–yearrange is written using anen dash(–,–or{{ndash}},or{{nbnd}}for a non-breaking en dash), not an em dash, hyphen, or slash; this dash isunspaced(that is, with no space on either side); and the end year is usually given in full:
  • 1881–1882;1881–1886(not1881–86);1881–1892(not1881–92)
    • Markup:1881{{ndash}}1882or1881–1882
  • Although non-abbreviated years are generallypreferred,two-digit ending years(1881–82,but never1881–882or1881–2)maybe used in any of the following cases: (1) two consecutive years; (2)infoboxesand tables where space is limited (using a single format consistently in any given table column); and (3) in certain topic areas if there is a very good reason, such as matching the established convention of reliable sources.For consistency, avoid abbreviated year ranges when they would be used alongside non-abbreviated ranges within an article (or related pages, if in titles). Never use abbreviated years for ranges across centuries (1999–2000,not1999–00) or for years from the first millennium (886–887,not886–87).
  • Theslash notation(2005/2006) may be used to signify a fiscal year or other special period, if that convention is used in reliable sources.
• Other "simple" ranges use anunspaceden dash as well:
  • day–day:5–7January 1979;January5–7, 1979;elections were held March 5–8.
  • month–month:the 1940 peak period was May–July;the peak period was May–July1940;(butthe peak period wasMay 1940 – July1940uses aspaceden dash;see below)
• In certain cases where at least one item on either side of the en dash contains a space, then aspaceden dash ({{snd}}) is used. For example:
  • between specific dates in different months:They travelledJune 3 – August18,1952;They travelled 3 June – 18August 1952
  • between dates in different years:
    • Charles Robert Darwin(12February1809 – 19 April1882) was an English naturalist...
      • Markup:12{{nbsp}}February 1809{{snd}}19{{nbsp}}April 1882or12 February 1809 – 19 April 1882
    • Abraham Lincoln(February12, 1809 – April15, 1865) was the 16th president of...
  • between months in different years:The exception was in force August1892 – January1903;The Ghent Incursion (March 1822 – January1, 1823) was ended by the New Year's Treaty
    • Markup:March 1822{{snd}}January{{nbsp}}1, 1823orMarch 1822 – January 1, 1823
  • Whereera designations,c.orother modifiersare present (see§ Uncertain, incomplete, or approximate dates):
    • if the modifierapplies to only one of the two endpoints of the range,use aspaceden dash:150 BCE – 50 BCE,5 BC – 12 AD,c. 1393 – 1414
    • if the modifierapplies to the range as a whole,disregardthe modifier:150–50 BCE,reigned 150 BCE – 50 BCE,reigned 150–50 BCE,r. c. 1393– 1414,r. 1393–1414.
• Use an en dash, or a word such asfromorbetween,but not both:from 1881 to 1886(notfrom 1881–1886);between June1 and July3(notbetween June1 – July3)

• MOS:DATEDsays "terms such as... 'present' should usually be avoided". For ranges, if"to present"or"–present"is used, the current year (or, in cases where necessary, date) of "present" at the time of writing should be included. Thus1982–present (as of 2024)– if writing in 2024 – is preferable to1982–present.If the "from" date has an internal space, a spaced en dash is used. Other constructions may be more appropriate in prose(see§ Statements likely to become outdated).An alternative form isSince 1982.

In tables and infoboxes where space is limited,pres.may be used (1982–pres.). Do not use incomplete-looking constructions such as1982–and1982–....

• Consider adding the{{As of}},or{{Update after}}templates to such constructions, depending on how important it is for editors to keep "present" up to date.

• For aperson still living:Serena Williams(born September26, 1981) is a...,not(September26, 1981 – )or(born on September26, 1981).

  Do not use*to indicateborn;useb.only where space is limited e.g. tables and infoboxes; use eitherbornorb.consistently in any given table column.

• Wherebirthdate is unknown:John Smith(died May1, 1622)orJohn Smith(died 1622)

  Do not use†to indicatedied;used.only where space is limited, with consistency within any given table column.

• Anovernight periodmay be expressed using a slash between two contiguous dates:the night raids of 30/31May 1942orraids of 31May/ 1June 1942.

  Or use an en dash: (unspaced)raids of 30–31May 1942;(spaced)raids of31May – 1June1942.

• The{{Age}}template can keep ages current in infoboxes and so on:
  • {{age|1989|7|23}}returns:34
  • {{age|1989|7|23}}-year-oldreturns:34-year-old
  • {{age|1989|7|23}} years oldreturns:34 years old
• Date mathematics templatesare available for other age calculations.

Uncertain, incomplete, or approximate dates

• To indicate "around", "approximately", or "about", the use of the{{circa}}template is preferred at first occurrence over justc..At later occurrences,c.is preferred overcirca,c,ca,ca.,around,approximately,orapprox.:
  • John Sayer(c. 1750– 2October 1818)...
  • the Igehalkid dynasty of Elam,c. 1400BC...
• Where both endpoints of a range are approximate,c.should appear before each date (the two-argument form of{{circa}}does this):
  • Dionysius Exiguus(c. 470– c. 540)...(notDionysius Exiguus(c.470 – 540)...)
  • Rameses III(reignedc. 1180– c. 1150BCE)...(notRameses III(reignedc.1180 – 1150BCE)...)
• Where birth/death limits have been inferred from known dates of activity:
  • Offa of Mercia(before 734 – 26July 796)...
  • Robert Menli Lyon(1789 – after 1863)...
  • Ambrose Gwinnett Bierce(June 24, 1842 – after December 26, 1913)...
• When birth and death dates are unknown, but the person is known to have been active ( "flourishing" ) during certain years,fl.,[[Floruit|fl.]],or{{fl.}}may be used:
  • Jacobus Flori(fl.1571–1588)...
  • Jacobus Florifils(fl. c. 1600– 1616)...

The corresponding template{{r.}}produces reign output:r. 540–562,though it is often clearer to write outreigned 540–562,especially in the lead. With both of these templates, linked forms should not be used on disambiguation pages, and "active" followed by the range is a better alternative for occupations not relating to the composition of works, whether it be musical, grammatical, historical, or any other such work.

• When a date is known to be either of two years (e.g. from aregnalorAHyear conversion, or a known age at death):
  • Anne Smith(born 1912 or 1913; died 2013)...
• Other forms of uncertainty should be expressed in words, either in article text or in a footnote:April14, 1224 (unattested date).Do not use a question mark (1291?), because it fails to communicate the nature of the uncertainty.
• Wherec.or a similar form appearswhich applies only to one of the two endpoints of the range,use a spaced en dash ({{snd}}).
  • Examples:1896 – after 1954,470 –c. 540,c. 470– 540,c. 470– c. 540.
  • Markup:1896{{snd}}after 1954,470{{snd}}{{c.|540}},{{c.|470}}{{snd}}540,{{c.|470|540}}.
• Where a modifierapplies to the range as a whole,such asfl.andr.,use a spaced or unspaced en dash as appropriate to the range if this modifier is disregarded.
  • Examples:fl.1571–1588,fl. c. 1600– 1616,r. c. 1353– 1336BC,r. 1989–2019CE,r. 2019CE – present.
• Some modifiers, such astraditionally,around,BH,andCE,sometimes apply to only one endpoint, and sometimes to the whole range. Whether the en dash should be spaced or unspaced should still be determined by the above guidelines, but consider rephrasing if the result is ambiguous or possibly confusing.
  • traditionally 1571–1588andtraditionally 1571 – 1588mean two different things, which may not be obvious to the reader.
  • traditionally 1585 –c. 1590can have two different meanings, and which one is meant may not be clear.
  • 400 BCE – 200clearly hasBCEapplying only to one endpoint, but the range is ambiguous. Consider using400–200 BCE,400 BCE – 200 BCE,or400 BCE – 200 CE,depending on what is meant.
  • Technically,Taishō13 – 57is currently unambiguous (because there is no Taishō 57), but it is better to use both era designations in this case:Taishō13 –Shōwa57.
• Ideally a non-breaking space should follow very short modifiers such asc.,fl.,r.,b.,andd.

Times of day

Context determines whether the12-or24-hourclock is used. In all cases, colons separate hours, minutes, and (where present) seconds, e.g.1:38:09pmor13:38:09.Use figures (11a.m.or12:45p.m.) rather than words (twelve forty-five p.m.).

• 12-hour clock timesend with lower-casea.m.orp.m.,oramorpm,preceded by anon-breaking space,e.g.2:30p.m.or2:30pm(markup:2:30{{nbsp}}p.m.or2:30{{nbsp}}pm), not2:30p.m.or2:30pm.Hours should not have a leading zero (e.g.2:30p.m.,not02:30p.m.). Usually, usenoonandmidnightrather than12 pmand12 am;whether "midnight" refers to the start or the end of a date should be explicitly specified unless clear from the context. Where several times that are all a.m. or all p.m. appear in close proximity, thena.m.orp.m.need be given only once if there is no risk of confusion.
• 24-hour clock timeshave no a.m., p.m., noon or midnight suffix, and include a colon (15:30not1530). Hours under 10 should have a leading zero (08:15). The time00:00refers to midnight at the start of a date,12:00to noon, and24:00to midnight at the end of a date, but24should not be used for the first hour of the next day (e.g. use00:10for ten minutes after midnight, not24:10).

Time zones

Give dates and times appropriate to thetime zonewhere an event took place. For example, the date of theattack on Pearl Harborshould be December7, 1941 (Hawaii time/​date). Give priority to the place at which the event had its most significant effects; for example, if a hacker in Monaco attacked a Pentagon computer in the US, use the time zone for the Pentagon, where the attack had its effect. In some cases, the best solution may be to add the date and time inCoordinated Universal Time(UTC). For example:

8p.m.Eastern Standard Timeon January15, 2001 (01:00UTC, January16)

Alternatively, include just theUTC offset:

21:00British Summer Time(UTC+1) on 27July 2012

Rarely, the time zone in which an event took place has since changed; for example, China until 1949 was divided intofive time zones,whereas all of modern China is one time zone;UTC+8.Similarly, the term "UTC" is not appropriate for dates before this system was adopted in 1960;Universal Time(UT) is the appropriate term for the mean time at theprime meridian (Greenwich)when it is unnecessary to specify the precise definition of the time scale. Be sure to show the UTC or offset appropriate to the clock time in use at the time of the event, not the modern time zone, if they differ.

Days of the week

• Where space is limited (e.g. tables), days of the week may be abbreviated asSun,Mon,Tue,Wed,Thu,Fri,Sat(without dots, i.e. notSun.,Mon.,etc.).

Seasons of the year

• Avoid using seasons to refer to a particular time of year, as they are often unduly ambiguous:Spring 1995began in the Southern Hemisphere six months after it did in the Northern Hemisphere; winter spans two calendar years in the Northern Hemisphere, but not in the Southern Hemisphere. Moreover, areas near the Equator have onlywetanddry seasons.Unambiguous alternatives includeearly1995;the second quarter of 1995;March to June1995;spent the southern autumn in Antarctica.
  • Referring to a season by name is appropriate when it is part of a conventional name or designation (annual mid-winter festival;the autumn harvest;the court's winter term;the magazine's summer 2015 issue).
• Season names are generally not capitalized (a hot summer), except when personified (Old Man Winter) or when part of a formal name (2018Winter Olympics;Arab Spring) that is capitalized under theguidelines for capitalization.They are capitalized when part of the title of a work (Science Fiction Quarterly,Summer 1942), except that seasonal editions may be lower-cased in running text (the Summer 1985 issue ofInterzoneorthe summer 1985 issue ofInterzone).

Decades

• To refer to a decade as a chronological periodper se(not with reference to a social era or cultural phenomenon), always use four digits and ans,as inthe1980s.Do not usethe1980's,orthe1980‑ies.
  • Prefixes should be hyphenated (themid‑1980s;pre‑1960s social attitudes).
  • Adjectives should not be hyphenated (the late 1950s, the early 1970s).
• For a social era or cultural phenomenon associated with a particular decade:
  • Two digits (with a preceding apostrophe) may be used as an alternative to four digits, but only in well-established phrases seen in reliable sources:theRoaring'20s;theGay'90s;condemning the '60s counterculture—butgrew up in 1960s Boston, moving to Dallas in1971.Do not write:the90's;the90s;orthe90s'.
  • Another alternative (where seen in reliable sources) is to spell the decade out, capitalized:changing attitudes of the Sixties.

Centuries and millennia

The sequence of numbered years in dates runs...2BC, 1BC, 1AD, 2AD...;there is no "year zero".

• Treat the 1st century AD as years1–100,the 17th century as1601–1700,and the second millennium as1001–2000;similarly, the 1st century BC / BCE was100–1BC / BCE, the 17th century BC / BCE was1700–1601BC / BCE, and the second millennium2000–1001BC / BCE.
• Centuries and millennia are identified using either Arabic numerals (the 18th century) or words (the second millennium), with in-article consistency (MOS:ORDINALnotwithstanding). When used adjectivally they contain a hyphen (nineteenth-century paintingor19th-centurypainting). Do not use superscripts (19^thcentury).
• Do not capitalize (the best Nineteenth-century paintings;during the Nineteenth Century)
• Do not useRoman numerals(XVIIIcentury).
• The 18th centuryrefers to the period (1701–1800), while strictlythe 1700srefers either to (1700–1799) or (1700–1709)
  • When using forms such asthe 1900s,ensure there is no ambiguity as to whether the century or the decade is meant.
• SeeWP:Manual of Style § En dashesfor use of hyphens and dashes in obscure situations.

Long periods of time

• When the term is frequent, combineyr(years) orya(years ago) withk(thousand):kya,kyr;M(million):Mya,Myr;andb(short-scalebillion):bya,byr.(SeeYear § Abbreviations yr and yafor more information.)
• In academic contexts,annus-based units are often used with anSI prefix:ka(kiloannus),Ma(megaannus), andGa(gigaannus).(SeeYear § SI prefix multipliersfor more information.)
• Show the meaning parenthetically, and consider linking to the appropriate section of theYeararticle(Year § Abbreviations yr and yaorYear § SI prefix multipliers)on first occurrence and where the use is a standalone topic of interest. In source quotations, use square brackets:"a potassium-argon date of 35.1Mya [million years ago]... "

Numbers

"MOS:FIGURE" redirects here. Not to be confused withMOS:IMAGE.

Numbers as figures or words

Information on specific situations is scattered elsewhere on this page.

Generally, in article text:

• Integers from zero to nine are spelled out in words.
• Integers greater than nineexpressible in one or two wordsmay be expressed either in numerals or in words (16orsixteen,84oreighty-four,200ortwo hundred). When written as words, integers from 21 to 99 that are not multiples of 10 are hyphenated (including when part of a larger number):fifty-sixandfifty-six thousand,butfivehundredandfivethousand.

Notes and exceptions:

• Avoid beginning a sentence with a figure:
  • Use:There were many matches;23 ended in a draw.Or:There were many matches.Twenty-three ended in a draw.
  • Not:There were many matches.23 ended in a draw.
  • Use:No elections were held in 1945 and 1950.
  • Not:1945 and 1950 had no elections.(Nor:Nineteen forty-five and 1950 had no elections–comparable numbers should be both written in words or both in figures.)
• In tables and infoboxes, quantities are expressed in figures (Years in office:5); but numbers within a table's explanatory text and comments follow the general rule.
• Numbers in mathematical formulae are never spelled out (3 < π <22/7notthree < pi < twenty-two sevenths), and "numbers as numbers" are rarely spelled out in other mathematical contexts (the first three primes are 2, 3, and 5notthe first three primes are two, three, and five;butzero-sum gameandroots of unity).
• Sport scores and vote tallies should be given as numerical figures (a25–7victory;passed with 7 ayes, 2 nays, and 1 abstention,thoughpassed with 7 ayes, 2 nays, and no abstentionswould be acceptable, instead of...0 abstentions).
• Comparable values nearby one another should be all spelled out or all in figures, even if one of the numbers would normally be written differently:patients' ages were five, seven, and thirty-twoorages were5, 7, and32,but notages werefive, seven, and 32.
  • Similar guidance applies where "mixed units" are used to represent a single value (as is often done with time durations, and in the imperial and US customary systems):5 feet 11 inchestall;five feet eleven inchestall;3 minutes 27 seconds;three minutes twenty-seven seconds.
• Adjacent quantities not comparable should ideally be indifferent formats:twelve 90-minute volumesor12 ninety-minute volumes,not12 90-minute volumesortwelve ninety-minute volumes.
  • Avoid awkward juxtapositions:On February 25, 2011, twenty-one more were chosen,notOn February 25, 2011, 21 more were chosen.
• Sometimes figures and words carry different meanings; for example,Every locker except one was searchedimplies there is a single exception (without specifying which), whileEvery locker except1 was searchedimplies that locker number1 was the only locker not searched.
• Proper names, technical terms, and the like are never altered:10 Downing Street,Nine Inch Nails,Channel 8,Seven Samurai,The Sixth Sense,Chanel No.5,Fourth Estate,The Third Man,Second Coming,First Amendment,Zero Hour!,"Less than Zero",C7 vertebra.
• Figures as figures: Use a figure when the figure itself (itsglyph,shape, etc.) is meant:a figure-8 pattern;in the shape of the numeral6.(SeeWikipedia:Manual of Style/Text formatting § Words as words.)
• Only figures are used with unitsymbols(12 minnottwelve min); but figures or words may be used with unitnames(12 minutesortwelve minutes), subject to the provisions above.

Other numbers

• Other numbers are given in numerals (3.75,544) or in forms such as21million(orbillion,trillion,etc. – but rarelythousandorhundred). Markup:21{{nbsp}}million
  • Billionandtrillionare understood to represent theirshort-scalevalues of 10⁹(1,000,000,000) and 10¹²(1,000,000,000,000), respectively. Keep this in mind when translating articles from non-English or older sources.
  • M(unspaced, capitalized) orbn(unspaced), respectively, may be used for "million" or "billion" after a number, when the word has been spelled out at the first occurrence (Her estate of £61million was split among her husband (£1M), her son (£5M), her butler (£10M), and her three Weimaraners (£15M each).).
  • SI prefixes and symbols, such asmega-(M),giga-(G) andtera-(T), should be used only with units of measure as appropriate to the field and not to express large quantities in other contexts. Examples of misuse:In a population of 1.3Gpeople, 300megadeaths would be expected.
  • Sometimes, thevariety of Englishused in an article may suggest the use of a numbering system other than the Western thousands-based system. For example, theIndian numbering systemis conventionally used for certain things (especially monetary amounts) inSouth Asian English.This is discouraged in Wikipedia articles byWP:Manual of Style § Opportunities for commonality.
    • When it is done anyway, for contextually important reasons, link the first spelled-out instance of each quantity (e.g.[[crore]],which yields:crore). If no instances are spelled out, provide a note after the first instance, directing the reader to the article about the numbering system.
    • Provide a conversion to Western numbers for the first instance of each quantity (For Indian figures, the templates{{lakh}}and{{crore}}may be used for this purpose), and provide conversions for subsequent instances if they do not overwhelm the content of the article. For example, writethreecrore(thirty million).When converting a currency amount, use the exchange rate that applied at the time being written about; the{{FXConvert}}template can be used for this purpose, or specialized templates for a currency such as{{INRConvert}}(for Indian Rupees) or{{KRWConvert}}(for Korean Won) can be used.
    • Group digits in Western thousands-based style (e.g.,30,000,000;not3,00,00,000);see§ Delimiting (grouping of digits),below.
    • An article's variety of English does not uniquely determine its formatting of numbers. Other considerations – such as conventions used in mathematics, science, and engineering – may also apply. In general, choice and order of formats and conversions is a matter of editorial discretion and consensus at the article.

Ordinals

"MOS:1ST" redirects here. For the guideline on the first sentence in articles, seeMOS:FIRST.

• The general principles set out in§ Numbers as figures or wordsapply to ordinals. In particular, do not start a sentence with a figure, and generally usefirstthroughninth,not1stthrough9th,for single-digit ordinals.
• In "suffix" forms, use two-letter suffixes:1st, 2nd, 3rd, 4thand so on (2ndBattalionnot2dBattalion). Do not superscript (e.g.123^rd).
• Do not use ordinals for dates (seeMOS:BADDATE).
• In English text, do not use a dot (.) or theordinal indicator(º). The masculineºor feminineªordinal indicator is acceptable in names, quotations, etc. from languages that conventionally use it. An Italian example:313º Gruppo Addestramento Acrobaticonot313º Acrobatic Training Grouporthe 313º.Use HTML markup for languages that do not have a special character but conventionally use a superscript, like2^ein French.
• Regnal numbersare normally written with ASCIIRoman numerals(without suffix, e.g.Elizabeth IInotElizabeth IIndorElizabeth 2nd).

Number ranges

Likedate ranges,number ranges and page ranges should state the full value of both the beginning and end of the range, separated by anen dash:pp.1902–1911orentries342–349.Except within quotations, avoid abbreviated forms such as1902–11or342–9,which are not understood universally, are sometimes ambiguous, and can cause inconsistent metadata to be created in citations.

Sport scores, vote tallies, etc.

Sport scores, vote tallies, or other presentations that juxtapose two opposing quantities use an unspaced en dash:

• Smith beat Jones7–3.
• Polls predicted Alice would defeat Bob74–20percent, with 6 percent undecided.

To avoid potential line breaks, use{{nowrap}}around the entire score construction, or use{{nbnd}}instead of{{ndash}}.

Singular versus plural

• Nouns followingsimple fractionsare singular (took1⁄4dose;net change was −1⁄2point;3⁄2dose).
• Nouns followingmixed numbersare plural (11⁄2doses;another 43⁄4miles).
• Nouns following the lone, unsigned digit 1 (one) are singular, but those following other decimal numbers (i.e. base-10 numbers not involving fractions) are plural (increased 0.7 percentage points;365.25days;paid 5 dollars per work hour, 1 dollar per travel hour, 0 dollars per standby hour;increased by 1pointbutnet change +1points;net change −1points;net change 1.0points).
• The same rules apply to numbers given in words (one dose;one and one-half doses;zero dollars;net change of negative one points).

Fractions and ratios

• Where numerator and denominator can each be expressed in one word, a fraction is usuallyspelled out(e.g.a two-thirds majority;moved one-quarter mile); use figures if a fraction appears with a symbol (e.g.1⁄4mi(markup:{{frac|1|4}}mi), nota quarter of a miorone-quarter mi). A common exception is a series of values:The distances were1+1⁄4,2⁄3and1⁄2mile, respectively.
• Mixed numbersmay be given in figures or words (perhaps applying the guidanceaboveto the integer part). If given in figures, they are unspaced (notPlatform 93⁄4orPlatform 9-3⁄4butPlatform9+3⁄4(markup:{{frac|9|3|4}})). In any case the integer and fractional parts should be consistent (notPlatform nine and3⁄4).
• Metric (SI) measurements generally use decimals, not fractions (5.25mm,not51⁄4mm).
• Non-metric (imperial and US customary) measurements may use fractions or decimals (51⁄4inches;5.25inches); the practice of reliable sources should be followed, and within-article consistency is desirable.
• In science and mathematics articles, mixed numbers are rarely used (use4/3the originalrather than11/3times the original voltage). The use of{{frac}}is discouraged;instead use one of these styles:
  • $\textstyle {\frac {1}{2}}$(markup:<math>\textstyle\frac{1}{2}</math>)
  • 1/2(markup:{{sfrac|1|2}})
  • 1/2(markup:1/2)
• Do not useprecomposed fractioncharacters such as½(deprecated markup:&frac12;or&#189;).
  • Except: If ¼, ½, and ¾are the only fractions needed, they may be used in an article, or category name, maintaining typographical consistency within an article where possible. (Examples:Floppy disk,Ranma ½,chess notation,Category:4 ft 6½ in gauge railways‎.)
  • For other fractions, where templates cannot be used due to technical limitations, use the ASCII representation with spaces. For example,Category:4 ft 10 7/8 in gauge railways.
• Ordinal suffixes such as-thshould not be used with fractions expressed in figures (noteach US state has 1/50th of theSenate'svotes;1/8th mile,butone-fiftieth of theSenate'svotes;1/8 mile;one-eighth mile).
• For dimensionless ratios (i.e. those without accompanying units), place a colon between integers, or placetobetween numbers-as-words:favored by a 3:1 ratioora three-to-one ratio,nota 3/1 ratioora 3–1 ratio.The same style is used to expressoddsin sport, gambling, and other statistical predictions.
  • Use a colon (spaced) when one or more decimal points is present(a 3.5:1 ratio(markup:a 3.5: 1 ratio)).
  • Do not use the colon form where units are involved (dissolve using a3 ml: 1 g ratio)‍—instead seeratiossection of table at§Unit names and symbols,below.

See also:Wikipedia:Manual of Style/Mathematics § Fractions

Decimals

• Use a period/full point (.) as thedecimal separator,nevera comma:6.57,not6,57.
• Numbers between −1 and +1 require a leading zero (0.02,not.02); exceptions are sporting performance averages (.430batting average) and conventional terms such as.22caliber.
• Although repeating digits may be indicated with anoverbar(e.g.14.31{{overline|28}}gives14.3128), users of screen readers will not hear any indication of the overbar. Apart from in mathematics articles, consider rounding to a reasonable resolution instead (e.g. ahalf farthing≈£0.00052not£0.00052083,aninch≈0.333palmsnot0.3palms), or showing initial repeats before the overbar (e.g. 0.333). If overbars are used, consider explaining the notation on first use. Do not write e.g.14.31(28)because it resemblesnotation for uncertainty.

Grouping of digits

• In general, digits should be grouped and separated either by commas or by narrow gaps (nevera period/full point).
  • Grouping with commas
    • Left of the decimal point, five or more digits are grouped into threes separated by commas (e.g.12,200;255,200km;8,274,527th;1⁄86,400).
    • Numbers with exactly four digits left of the decimal point may optionally be grouped (either1,250or1250), consistently within any given article.
    • Do not use commas to the right of the decimal point, or with numbers not in base 10.
    • Markup:{{formatnum:}}produces this formatting.
  • Grouping with narrow gaps
    • Digits are grouped both sides of the decimal point (e.g.6543210.123456;520.01234°C;101325/760).
    • Digits are generally grouped into threes. Right of the decimal point,usualpractice is to have a final group of four in preference to leaving an "orphaned" digit at the end (99.1234567,but99.1234567would also be acceptable). In mathematics-oriented articles long strings may be grouped into fives (e.g.3.14159265358979323846...).
    • This style is especially recommended for articles related to science, technology, engineering or mathematics, though in these contexts there may be cases in which grouping confuses rather than clarifies. (For example, for fractions written in horizontal format, adding spaces to a fraction like 123456/127 would cause it to be misread as 123456/127or 123456/127.)
    • Markup: Templates{{val}}or{{gaps}}may be used to produce this formatting. Note that use ofanyspace character as a separator in numbers, including non-breaking space, is problematic forscreen readers.(See§ Non-breaking spaces.)Screen readers read out eachgroupof digits as separate numbers (e.g.30{{thin space}}000is read as "thirty zero zero zero" ). The output of{{val}}and{{gaps}}is compatible with screen readers.
• Delimiting style should be consistent throughout a given article.
  • Either use commas or narrow gaps, but not both in the same article.
  • Either group the thousands in a four-digit number or do not, but not mixed use in the same article.
  • However, grouping by threes and fives may coexist.
• Four-digit page numbers and four-digit calendar years should never be grouped (notsailed in 1,492,butdynasty collapsed around 10,400BCorby13727AD,Vega will be the northern pole star).

Percentages

• Throughout scientific/​technical articles, and in tables and infoboxes inanyarticle, the symbol%is generally preferred. No space (3%,not3%), and do not use mixed forms such asthree%.
• The bodyof non-scientific/​non-technical articles may use either the%symbol or the word(s)percent(American English) orpercent(British English):10 percent;ten percent;4.5 per cent.
• Ranges are written10–12%,ten to twelve per cent,orten to twelve percent;notten–twelve per cent,10%–12%,or10 to 12%.
• When expressing the difference between two percentages, do not confuse a percentage change with a change inpercentage points.

Scientific and engineering notation

• Scientific notationalways has a single nonzero digit to the left of the point: not60.22×10²²,but6.022×10²³.
• Engineering notationis similar, but with the exponent adjusted to a multiple of three:602.2×10²¹.
• Avoid mi xing scientific and engineering notations:A2.23×10²m²region covered by234.0×10⁶grains of sand.
• In a table column (or other presentation) in which all values can be expressed with a single power of 10, consider giving e.g.×10⁷once in the column header, and omitting it in the individual entries. (Markup:{{e|7}})
• In both notations, the number of digits indicates the precision. For example,5×10³means rounded to the nearest thousand;5.0×10³to the nearest hundred;5.00×10³to the nearest ten; and5.000×10³to the nearest unit.

Markup:{{val}}and{{e}}may be used to format exponential notation.

Uncertainty and rounding

• Where explicit uncertainty information (such as amargin of error) is available and appropriate for inclusion, it may be written in various ways:
  • (1.534 ± 0.035) × 10²³m
  • 12.34m²± 5%(not used with scientific notation)
  • 15.34^+0.43
    _−0.23× 10²³m
  • 1.604(48) × 10⁻⁴J(equivalent to(1.604 ± 0.048) × 10⁻⁴J)
  • Polls estimated Jones's share of the vote would be 55 percent, give or take about 3 percent
  • Markup:{{+-}},{{su}},and{{val}}may be used to format uncertainties.
• Where explicituncertainty is unavailable(or is unimportant for the article's purposes), round to an appropriate number ofsignificant digits;the precision presented should usually be conservative. Precise values (often given in sources for formal or matter-of-record reasons) should be used only where stable and appropriate to the context, or significant in themselves for some special reason.
  • The speed of light is defined to be 299,792,458m/s
  • butParticle velocities eventually reached almost two-thirds the 300-million-metre-per-second speed of light.
  • checks worth $250 (equivalent to $1,800 in 2016)(not$1,845.38 in 2016)
  • The city's 1920 population was 10,000(notpopulation was 9,996– an official figure unlikely to be accurate at full precision)
  • butThe town was ineligible because its official census figure (9,996) fell short of the statutory minimum of ten thousand(unusual case in which the full-precision official figure is truly informative)
  • The accident killed 337 passengers and crew, and 21 people on the ground(likely that accurate and precise figures were determined)
  • At least 800 persons died in the ensuing mudslides(unlikely that any precise number can be accurate, even if an official figure is issued)
  • orOfficials listed 835 deaths, but the Red Cross said dozens more may have gone unreported(in reporting conflicting information, give detail sufficient to make the contrast intelligible)
  • The jury's award was $8.5million(not$8,462,247.63).The appeals court reduced this to $3,000,001 (one dollar in actual damages, the remainder in punitive damages).
• The number of decimal places should be consistent within a list or context (The response rates were 41.0 and 47.4 percent, respectively,not41 and 47.4 percent), unless different precisions are actually intended.
• It may sometimes be appropriate to note thelackof uncertainty information, especially where such information is normally provided and necessary for full interpretation of the figures supplied.
  • A local newspaper poll predicted 52 percent of the vote would go to Smith, but did not include information on the uncertainty of this estimate
• The{{undue precision}}template may be added to figures appearing to be overprecise.
• Avoid using "approximately", "about", and similar terms with figures that have merely been approximated or rounded in a normal and expected way, unless the reader might otherwise be misled.
  • The tallest player was 6 feet 3 inches(not... about 6 feet 3 inches– heights are conventionally reported only to the nearest inch, even though greater precision may be available in principle)
  • butThe witness said the assailant was about 5 feet 8 inches tall( "about" because here the precise value is unknown, with substantial uncertainty)
• The reader may be assumed to interpret large round numbers (100,000 troops) as approximations. Writing a quantity in words (one hundred thousand troops), especially if theindefinite article(a/an) is used instead of the wordone(a hundred thousand troops), can further emphasize its approximate nature.
• See§ Unit conversionsbelow for precision issues when converting units.

Non–base-10 notations

• In computer-related articles, use the prefix0xfor hexadecimal and0bfor binary,unless there is a strong reason to use some other notation.Explain these prefixes in the article's introduction or on first use.
• In all other articles, use{{base}}:137₉,201₃.Markup:{{base|137|9}},{{base|201|3}}
• Forbasesabove 10, use symbols conventional for that base (as seen in reliable sources) e.g. forbase 16use0–9 and A–F.
• For octal, use 200₈.Avoid using a prefix unless it is needed for computer code samples, in which case explain the prefix on first use.

Mathematical formulae

Main page:Wikipedia:Manual of Style/Mathematics

There are multiple ways to display mathematical formulae, covered in detail atWikipedia:Manual of Style/Mathematics § Typesetting of mathematical formulae.One uses special MediaWiki<math>...</math>markup usingLaTeXsyntax, which is capable of complex formulae; the other relies on conventionalizedHTMLformatting of simple formulae.

The<math>markup is displayed as aPNGimage by default. Logged-in users can optionally have it rendered inMathML,or in HTML (viaMathJax); detailed instructions are atHelp:Displaying a formula.

Do not put<math>markup in headings.

Units of measurement

Unit choice and order

Quantities are typically expressed using an appropriate "primary unit", displayed first, followed, when appropriate, by a conversion in parentheses e.g.200 kilometres (120 mi).For details on when and how to provide a conversion, see the section§ Unit conversions.The choice of primary units depends on the circumstances, and should respect the principle of "strong national ties",where applicable:

• Innon-scientific articles with strong ties to the United States,the primary units areUS customary(pounds,miles,feet, inches, etc.)
• Innon-scientific articles with strong ties to the United Kingdom,the primary units for most quantities are metric or other internationally used units,except that:
  • UK engineering-related articles, including those on bridges and tunnels, generally use the system of units in which the subject project wasdrawn up(but road distances are given in imperial units, with a metric conversion – see next bullet);
  • the primary units for distance/​length, speed and fuel consumption aremiles,miles per hour, and miles per imperial gallon (except for short distances or lengths, where miles are too large for practical use);
  • the primary units for personal height and weight are feet​/inches and stones/​pounds;
  • imperial pints are used for quantities of draught beer/​cider and bottled milk;
• Inall other articles,the primary units chosen will beSIunits (such as kilograms),non-SI units officially accepted for use with the SI,or such other units as are conventional in reliable-source discussions of the article topic (such asrevolutions per minute(rpm) forrotational speed,handsfor heights of horses, etc.)
  • the primary SI units for personal height and weight are centimetres and kilograms.

Special considerations:

• Quantities set via definition (as opposed to measured quantities) should be given first in the units used in the definition, even if this makes the structure of presentation inconsistent:During metrication, the speed limit was changed from 30mph (48km/h) to 50km/h (31mph).
  • Or useaboutto emphasize which is the statutory, exact value:...from 30mph (about 48km/h) to 50km/h (about 31mph).
• Nominal quantities (e.g.2×4lumber) require consideration of whether the article is concerned with the item's actual dimensions or merely with its function. In some cases, the nominal quantity may suffice; in others it may be necessary to give the nominal size (often in non-SI units), the actual size in non-SI units, and the actual size in SI units.
• Whenever a conversion is given, the converted quantity's value should match the precision of the source(see§ Unit conversions).
• Where the article's primary units differ from the units given in the source, the{{convert}}template's|order=flipflag can be used; this causes theoriginalunit to be shown as secondary in the article, and theconvertedunit to be shown as primary:{{convert|200|mi|km|order=flip}}→The two cities are 320 kilometres (200 mi) apart.

Unit conversions

See also:§ Currency conversions

Where English-speaking countries use different units for the same quantity, provide a conversion in parentheses:the Mississippi River is 2,320 miles (3,734 km) long;the Murray River is 2,508 kilometres (1,558 mi) long.But in science-related articles, supplying such conversion is not required unless there is some special reason to do so.

• Where animperial unitis not part of theUS customary system,or vice versa – and in particular, where those systems give a single term different definitions – a double conversion may be appropriate:Rosie weighed 80 kilograms (180 lb; 12 st 8 lb)(markup:{{convert|80|kg|lb stlb}});The carhad a fuel economy of 5 L/100 km (47 mpg_‑US;56 mpg_‑imp)(markup:{{convert|5|L/100km|mpgus mpgimp|abbr=on}}).
• Generally, conversions to and from metric units and US or imperial units should be provided, except:
  • When inserting a conversion would make a common or linked expression awkward (The four-minute mile).
  • In some topic areas (for example maritime subjects where nautical miles are the primary units, or American football whereyardsare primary) it can be excessive to provide a conversion for every quantity. In such cases consider noting that the article will use a particular unit – possibly giving the conversion factor to other, familiar units in a parenthetical note or a footnote – and link the first occurrence of each unit but not give a conversion every time it occurs. Applying this principle may require editorial discretion; for example, in scientific articles the expected level of reader sophistication should be taken into account.
• For units of measure that are obsolete, obscure outside of a particular specialty or geography (e.g.furlong), or not part of the SI or US customary systems (e.g.zolotnik), supply a parenthetical conversion into at least SI units. Convert each mention, unless this would be excessive given the context. Take care to distinguish between different definitions of the same unit if it has changed over time or differs geographically (e.g.cubit,batman). An approximate or range conversion is acceptable if the exact historical value is uncertain (e.g.stadion).
• Converted quantity values should use alevel of precisionsimilar to that of the source quantity value, sothe Moon is 380,000kilometres (240,000mi) from Earth,not(236,121mi).Small numbers, especially if approximate, may need to be converted to a range where rounding would cause a significant distortion, soabout one mile (1–2km),notabout one mile (2km).Be careful especially when your source has already converted from the units you're now converting back to. This may be evidenced by multiples of common conversion factors in the data, such as 160 km (from 100 miles).Seefalse precision.
• {{convert}}and otherconversion templatescan be used to convert and format many common units, and have options to respect significant figures. To avoid problems with rounding and significant figures, for input to conversion templates use only the original quantity found in reliable sources, not one that a source has already converted. If required by the above rules, the conversion output can be displayed as the primary units with "order=flip". Conversion output can be displayed as the only units with "disp=out"; this retains the original quantity in wikitext for verification by editors.
• In adirect quotation,always retain the source units. Any conversions can be supplied either in the quote itself (in square brackets, following the original measurement) or in a footnote.Seefootnotingandciting sources.
• {{Units attention}}may be added to articles needing general attention regarding choice of units and unit conversions.

Unit names and symbols

Definitions:

• Examples ofunit names:foot, metre, kilometre, (US:meter, kilometer).
• Examples ofunit symbols:ft, m, km.

• Unit names and symbols should follow the practice of reliable sources.
• In prose, unit names should be given in full if used only a few times, but symbols may be used when a unit (especially one with a long name) is used repeatedly, after spelling out the first use (e.g.Up to 15 kilograms of filler is used for a batch of 250kg).
  • Exception: Certain units are generally represented by their symbols (e.g.°Crather thandegrees Celsius) even on first use, though their unit names may be used for emphasis or clarity (conversion of degrees Celsius to degrees Fahrenheit).
  • Exception: Consider usinginches(but notin.) in place ofinwhere the latter might be misread as a preposition‍—but not where the value is followed by a parenthesized conversion e.g.bolts 5in (12.7cm) long,or is part of such a conversion (bolts 12.7cm (5in) long).
• Where space is limited, such as in tables, infoboxes, parenthetical notes, and mathematical formulas, unit symbols are preferred.
• Units unfamiliar to general readers should be presented as a name–symbol pair on first use, linking the unit name (Energies rose from 2.3megaelectronvolts(MeV) to 6MeV).
• Ranges use unspaced en dash ({{ndash}}) if only one unit symbol is used at the end (e.g.5.9–6.3kg), and spaced en dash ({{snd}}) if two symbols are used (e.g.3μm – 1mm); ranges in prose may be specified using either unit symbol or unit names, and units may be stated either after both numerical values or after the last (all acceptable:from 5.9 to 6.3 kilograms;from 5.9 kilograms to 6.3 kilograms;from 5.9 to 6.3kg;from 5.9kg to 6.3kg).
• Length–width, length–width–height and similar dimensions may be separated by the multiplication sign (×or×) or the wordby.
  • The×symbol is preceded by a space (preferably non-breaking), and followed by a space (which may also be non-breaking in short constructions), and each number should be followed by a unit name or symbol:
    • 1 m × 3 m × 6 m,not1 × 3 × 6 m,(1 × 3 × 6) m,nor1 × 3 × 6 m³
    • a metal plate 1 ft × 3 ft × 0.25 in
    • a railroad easement 10 ft × 2.5 mi
  • Withby,the unit need be given only once if it is the same for all dimensions:1 by 3 by 6 metresor1 by 3 by 6 m
  • The unspaced letterxmay be used in common terms such as4x4.

General guidelines on use of units

Aspect	Guideline	Acceptable	Unacceptable
Unit names and symbols	Except as listed in the§ Specific unitstable below, unitsymbolsare uncapi­tal­ized unless they are derived from a proper name, in which case the first letter (of the base unit symbol, not of any prefix) is capitalized.	8 kg 100 kPa	8 Kg 100 kpa
	Unit symbols are undotted.	38 cm of rope	38 cm.of rope
	Unitnamesare given in lower case except: where any word would be capital­ized, or where otherwise specified in the SI brochureor this Manual of Style.	A gallon is 4quarts. 4 pascals	A Gallon is 4Quarts. 4 Pascals
		He walked several miles. Miles of trenches were dug.
	The spelling of certain unit names (some of which are listed in§ Specific units,below) varies with thevariety of English followed by the article.
	Write unit names and symbols in upright (roman) type, except where emphasizing in context.	10m 29 kilograms	10m 29kilograms
		Thus each two-liter jug contained only twoquarts.
	Do not use precomposed unit symbol characters.		㎓, ㎦, ㎍, ㎖, ㎉
Numeric values	Do not spell out numbers before unitsymbols...	12min	twelvemin
	...but wordsorfigures may be used with unitnames.	twelve minutes 12 minutes
	Use a non-breaking space ({{nbsp}}or) between a number and a unitsymbol,or use{{nowrap}}...	29kg(markup:29 kgor{{nowrap|29 kg}})	29kg
	... though with certain symbolsnospace is used (see "Specificunits "table below)...	23°47′22″	23°47′22″
	... and a normal space is used between a number and a unitname.	29kilograms (markup:29kilograms)
	To form a value and a unitnameinto a compound adjective use a hyphen or hyphens...	a five-day holiday a five-cubic-foot box a 10-centimeter blade
	... but a non-breaking space (never hyphen) separates a value and unitsymbol.	a blade 10 cm long	a 10-cm blade
Plurals	SIunitnamesare pluralized by adding-sor-es...	1 ohm;10 ohms
	... except for these irregular forms.	1 henry;10 henries 1 hertz;10 hertz 1 lux;10 lux 1 siemens;10 siemens	10 henrys 10 hertzes 10 luxes 10 siemenses
	Some non-SI units have irregular plurals.	1 foot;10 feet	10 foots
		1 stratum;10 strata(unusual)	10 stratums
	Unitsymbols(in any system) are identical in singular and plural.	grew from 1 in to 2 in grew from 1 inch to 2 inches grew from one to two inches	grew from 1 in to 2 ins
Powers	Format exponents using <sup>, not special characters.	km2 (markup:km<sup>2</sup>)	km² (km&#178;)
	Or usesquaredorcubed(afterthe unit being modified).	ten metres per second squared	ten metres per squared second
	For areas or volumes only,squareorcubicmay be used (beforethe unit being modified).		ten metres per square second
		tons per square mile
	sqorcumay be used with US customary or imperial units, but not withSIunits.	15sqmi 3cuft	15sqkm 3cum
Products	Indicate a product of unitnameswith either a hyphen or a space.	foot-pound foot pound	footpound foot⋅pound
	Indicate a product of unitsymbolswith&sdot;or&nbsp;.	ms= millisecond m⋅sorms= metre-second
	Exception:In some topic areas, such as power engineer­ing, certain products take neither space nor&sdot;.Follow the practice of reliable sources in the article's topic area.	Wh,VA,Ah kWh,MVA,GAh
	To pluralize a product of unitnames,pluralize only the final unit. (Unitsymbolsare never pluralized.)	ten foot-pounds	ten feet-pounds
Ratios, rates, densities	Indicate a ratio of unitnameswithper.	meter per second	meter/second
	Indicate a ratio of unitsymbolswith a forward slash (/), followed by either a single symbol or a parenthesized product of symbols – do not use multiple slashes. Or use−1,−2,etc.	metre per second m/s m⋅s−1	mps
		kg/(m⋅s) kg⋅m−1⋅s−1	kg/m⋅s kg/m/s
	To pluralize a ratio of unitnames,pluralize only the numerator unit. (Unitsymbolsare never pluralized.)	ten newton-metres per second 10 N⋅m/s
	Some of the special forms used in the imperial and US customary systems are shown here...	mph= miles per hour mpg= miles per gallon psi=poundsper square inch
	... but only the slash or negative exponent notations are used with SI (and other metric) units.	g/m2 g⋅m−2	gsm
		km/h km⋅h−1	kph
Prefixes	Prefixes should not be separated by a space or hyphen.	kilopascal	kilo pascal kilo-pascal
	Prefixes are added without contraction, except as shown here:	kilohm megohm hectare	kiloohm megaohm hectoare
	Thedeci-,deca-,andhecto-prefixes should generally be avoided; exceptions include decibel, hectolitre, hectare, and hectopascal.	100 metres 0.1 km	1 hectometre
	Do not useMfor 103,MMfor 106,orBfor 109(except as noted elsewhere on this page forMandB,e.g.for monetary values)	3 km 8 MW 125 GeV	3 Mm 8 MMW 125 BeV
Mixed units	Mixed units are traditionally used with the imperial and US customary systems...	a wall 1 ft 1 in thick a wall 1 foot 1 inch thick a man 6 feet 2 inches tall a 6-foot 2-inch man a 6 ft 2 in man	1 ft , 1 in(no comma) 1 foot , 1 inch a man 6 foot 2 tall a 6-foot 2 man
		1 US fl pt 8 oz 1 US fl pt 8 US fl oz
	... and in expressing time durations...	1:30:07 1:30  1 h 30 min 7 s 01h30m07s	1:30′07″ 1:30′ 1 hr 30 min 7 sec 1 h 30 m 7 s
	... but are not used with metric units.	1.33 m 133 cm	1 m 33 cm

Note to table:

Specific units

• The following table lists only units that need special attention.
• TheSI Brochureshould be consulted for guidance on use of other SI and non-SI units.

Guidelines on specific units

Group	Unit name	Unit symbol	Comment
Length, speed	inch foot	in ft	Do not use′(′),″(″), apostrophe('), or quote("). Exception: in music,eight-foot pitchnotation describes organ stops and wind instrument lengths in feet. A prime may be used with an explanation on first use, e.g.a16 foot(16′) organ pedal stop;seeMOS:MUSIC.
	foot per second	ft/s(notfps)
	hand	horhh	Equal to 4 inches; used in measurement of horses. A dot may be followed by additional inches e.g.16.2 hhindicates16 hands 2 inches.
	knot knotindicated airspeed knotcalibrated airspeed knotequivalent airspeed knottrue airspeed knotgroundspeed	kn(notkt,Kt,orkN) KIASorkn KCAS KEAS KTAS kn(notKGS)	Used in aviation contexts for aircraft and wind speeds, and also used in some nautical and general meteorological contexts. When applied to aircraft speeds,knmeansKIASunless stated otherwise; ifknis used for calibrated airspeed, equivalent airspeed, true airspeed, or groundspeed, explicitly state and link to, upon first use, the type of speed being referred to (for instance,knequivalent airspeed,or, if severely short of space,knEAS); for airspeeds other than indicated airspeed, the use of the specific abbreviation for the type of airspeed being referred to (such asKEAS) is preferred. When referring to indicated airspeed, eitherknorKIASis permissible. Groundspeeds and wind speedsmustuse the abbreviationknonly.
	metre meter(US)	m
	micron	μm(notμ)	Markup:μmLink tomicrometre(for which micron is a synonym) on first use.
	astronomical unit	au (notA.U.,ua)	The preferred form isau.Articles that already useAUmay switch to au or continue with AU; seek consensus on the talk page.
	mile miles per hour nautical mile	mi mph nmiorNM(notnmorM)	In nautical and aeronautical contexts where there is risk of confusion with nautical miles, consider writing out references tostatute milesas e.g.5statutemilesrather than simply5miles.
Volume, flow	cubic centimetre cubic centimeter(US)	cm3	Markup:cm<sup>3</sup>
		cc	Non-SI abbreviation used for certainengine displacements.Link toCubic centimetreon first use.
	imperial fluid ounce imperial pint imperial quart imperial gallon US fluid ounce US dry pint US liquid pint US dry quart US liquid quart US gallon	imp fl oz imp pt imp qt imp gal US fl oz US dry pt US liq pt US dry qt US liq qt US gal	USorimperial(orimp) must be specified for all these units. fluidorflmust be specified for fluid ounces (to avoid ambiguity versusavoirdupois ounceandtroy ounce). For US pints and quarts,dryorliquid(liq) are needed to be fully unambiguous, though context determines whether or not to repeat those qualifiers on every use in a given article.
	cubic foot	cu ft(notcf)	Writefive million cubic feet,5,000,000cuft,or5×106cu ft,not5MCF.
	cubic foot per second	cu ft/s(notcfs)
	litre liter(US)	L(notlorℓ)	The symbol l (lowercase "el" ) in isolation (i.e. outside forms as ml) is easily mistaken for the digit1 or the capitalletter I ( "eye" )and should not be used.
	millilitre milliliter(US)	mlormL	Derivative units of the litre may use l (lowercase "el" ).
Mass, weight, force, density, pressure	gram kilogram	g kg	Notgramme,kilogramme
	long ton short ton	long ton short ton	Spell out in full.
	tonne metric ton(US)	t(notmt,MT,orMt)
	pound per square inch	psi
	troy ounce troy pound	oz t lb t	The qualifiertortroymust be specified where applicable. Use the qualifier avdp (avoirdupois) only where there is risk of confusion with troy ounce, imperial fluid ounce, US fluid ounce, or troy pound; but articles about precious metals, black powder, and gemstones should always specify which type of ounce (avoirdupois ortroy) is being used, noting that these materials are normally measured in troy ounces and grams.
	avoirdupois ounce avoirdupois pound	ozoroz avdp lborlb avdp
	carat	carat	Used to express masses of gemstones and pearls.
Purity	carat or karat	korKt(notktorK)	A measure of purity for gold alloys. (Do not confuse with the unit of mass with the same spelling.)
Time	second minute hour	s min h	Do not use&prime;(′),&Prime;(″), apostrophe(') or quote(") for minutes or seconds. See also the hours–minutes–seconds formats for time durations described in theUnit names and symbols table.
	year	a	Useaonly with anSI prefix multiplier(a rock formation 540Maold,notLife expectancy rose to 60a).
		yoryr	See§ Long periods of timefor all affected units.
Information, data	bit	bit(notborB)	See also§ Quantities of bytes and bits,below.Do not confuse bit/second or byte/second withbaud (Bd).
	byte	Borbyte(notboro)
	bit per second	bit/s(notbps,b/s)
	byte per second	B/sorbyte/s(notBps,bps,b/s)
Angle
	arcminute	′	Markup:{{prime}}(prime′not apostrophe/​single quote').No space (47′,not47′).
	arcsecond	″	Markup:{{pprime}}(double prime″not double-quote").No space (22″,not22″).
	degree	°	Markup: degree ° notmasculine ordinalºorring ̊.No space (23°,not23°).
Temperature	degree Fahrenheit	°F(notF)	Markup:12{{nbsp}}°C,not12°Cor12°{{nbsp}}C.Do not use theprecomposed charactersU+2103℃DEGREE CELSIUSorU+2109℉DEGREE FAHRENHEIT.
	degreeRankine	°R(notR)
	degree Celsius(notdegree centigrade)	°C(notC)
	kelvin(notdegree kelvin)	K(not°K)	Use a non-breaking space:12{{nbsp}}K(usethe normal Latin letter K,notU+212AKKELVIN SIGN). When writing out the unit (not usually necessary), pluralize, e.g.12 kelvins(seeKelvin#Orthography)
Energy	calorie small calorie gram calorie	cal	In certain subject areas,calorieis convention­ally used alone; articles following this practice should specify on first use whether the use refers to the small calorie or to the kilocalorie (large calorie). Providing conversions toSIunits (usually calories to joules or kilocalories to kilojoules) may also be useful. A kilocalorie (kcal) is 1000 calories. A calorie (small calorie) is the amount of energy required to heat 1 gram of water by 1°C. A kilocalorie is also a kilogram calorie.
	kilocalorie large calorie kilogram calorie (notCalorie –can be ambiguous)	kcal

Quantities of bytes and bits

In quantities ofbitsandbytes,the prefixeskilo-(symbolkorK),mega-(M),giga-(G),tera-(T), etc., are ambiguous in general usage. The meaning may be based on a decimal system (like the standardSIprefixes), meaning 10³,10⁶,10⁹,10¹²,etc., or it may be based on a binary system, meaning 2¹⁰,2²⁰,2³⁰,2⁴⁰,etc. The binary meanings are more commonly used in relation to solid-state memory (such asRAM), while the decimal meanings are more common for data transmission rates, disk storage and in theoretical calculations in modern academic textbooks.

Follow these recommendations when using these prefixes in Wikipedia articles:

• Following the SI standard, a lower-casekshould be used for "kilo-" whenever it means 1000 in computing contexts, whereas a capitalKshould be used instead to indicate the binary prefix for 1024 according to JEDEC. If, under the exceptions detailed further below, the article otherwise uses IEC prefixes for binary units, useKiinstead.
• Do not assume that the binary or decimal meaning of prefixes will be obvious to everyone. Explicitly specify the meaning of k and K as well as the primary meaning of M, G, T, etc. in an article ({{BDprefix}}is a convenient helper). Consistency within each article is desirable, but the need for consistency may be balanced with other considerations.
• The definition most relevant to the article should be chosen as primary for that article, e.g. specify a binary definition in an article on RAM, decimal definition in an article onhard drives,bit rates,and a binary definition for Windows file sizes, despite files usually being stored on hard drives.
• Where consistency is not possible, specify wherever there is a deviation from the primary definition.
• Disambiguation should be shown in bytes or bits, with clear indication of whether in binary or decimal base. There is no preference in the way to indicate the number of bytes and bits, but the notation style should be consistent within an article. Acceptable examples include:
  • A 64MB (64×1024²-byte)video card and a 100GB(100×1000³-byte)hard drive
  • A 64MB (64×2²⁰-byte)video card and a 100GB(100×10⁹-byte)hard drive
  • A 64MB(67,108,864-byte)video card and a 100GB(100,000,000,000-byte)hard drive
• Avoid combinations with inconsistent form such asA 64MB(67,108,864-byte)video card and a 100GB(100×1000³-byte)hard drive.Footnotes, such as those seen inPower Macintosh 5500,may be used for disambiguation.
• Unless explicitly stated otherwise, one byte is eight bits (seeByte § History).
• TheIEC prefixeskibi-(symbolKi),mebi-(Mi),gibi-(Gi), etc., are generally not to be used except:
  • when the majority of cited sources on the article topic use IEC prefixes;
  • in a direct quote using the IEC prefixes;
  • when explicitly discussing the IEC prefixes; or
  • in articles in which both types of prefix are used with neither clearly primary, or in which converting all quantities to one or the other type would be misleading or lose necessary precision, or declaring the actual meaning of a unit on each use would be impractical.

Currencies and monetary values

"WP:MONEY" and "WP:CURRENCY" redirect here. For the WikiProject focusing on articles about currencies, seeWikipedia:WikiProject Numismatics.

"WP:$" and "WP:£" redirect here. For the policy on paid editing, seeWikipedia:Paid-contribution disclosure.For the humor page, seeHelp:Buying Wikipedia.

Choice of currency

• Incountry-specific articles,such asEconomy of Australia,use the currency of the subject country.
• Innon-country-specific articles,such asWealth,use US dollars (US$123on first use, generally$123thereafter), euros (€123), or pounds sterling (£123).

Currency names

• Do not capitalize the names or denominations of currencies, currency subdivisions, coins and banknotes: nota Five-Dollar bill, four Quarters, and one Penny total six Dollars one Centbuta five-dollar bill, four quarters, and one penny total six dollars one cent.Exception:where otherwise required, as at the start of a sentence or in such forms asAustralian dollar.
• To pluralizeeuro,use the standard English plurals (ten euros and fifty cents), not theinvariant plurals used for European Union legislation and banknotes(ten euro and fifty cent). For the adjectival form, use a hyphenated singular (a two-euro pen and a ten-cent coin).
• Link the first occurrence of lesser-known currencies (e.g.Mongolian tögrögs).

Currency symbols

• In general, the first mention of a particular currency should use its full, unambiguous signifier (e.g.A$52), with subsequent references using just the appropriate symbol (e.g.$88), unless this would be unclear.Exceptions:
  • In an article referring to multiple currencies represented by the same symbol (e.g. the dollars of the US, Canada, Australia, New Zealand, and other countries –seeCurrency symbols § dollar variants) use the full signifier (e.g.US$orA$,but not e.g.$US123or$123 (US)) each time, except (possibly) where a particular context makes this both unnecessary and undesirable.
  • In articles entirely on US-related topics, all occurrences of theUS dollarmay be shortened ($34), unless this would be unclear.
  • For currencies that use a unit named the "pound":
    • Use the£symbol (U+00A3£POUND SIGN) for unambiguous referrals tosterling,the United Kingdom's currency. Avoid theU+20A4₤LIRA SIGN.
    • GBP,sterling's ISO 4217 code, should be used to disambiguate that currency from others. Avoid usingstg.orGB£.
    • For currencies other than sterling, use the symbol or abbreviation conventionally employed for that currency, if any.
• Link the first occurrence of lesser-known currency symbols (e.g.₮)
• If there is no common English abbreviation or symbol, follow theISO 4217standard.See alsoList of circulating currencies.

See also:Wikipedia:Manual of Style/Abbreviations § Unicode abbreviation ligatures

Currency formatting

• A point (full stop or period,.) – never a comma – is used as the decimal marker ($6.57,not$6,57).
• For the grouping of digits (e.g.£1,234,567) see§ Grouping of digits,above.
• Do not place a currency symbolafterthe accompanying numeric figures (e.g.123$,123£,123€) unless that is the normal convention for that symbol when writing in English:smaller British coins include 1p, 2p, and 5p denominations.
• Currency abbreviations preceding a numeric value areunspacedif they consist of a non Alpha betic symbol alone (£123or€123), or end with a non Alpha betic symbol (R$123); butspaced(using{{nbsp}}) if completely Alpha betic (R123orJOD123).
• Ranges should be expressed giving the currency signifier just once:$250–300,not$250–$300.
• millionandbillionshould be spelled out on first use, and (optionally) abbreviatedMorbn(both unspaced) thereafter:She received £70 million and her son £10M;the school's share was$250–300 million,and the charity's $400–450M.
• In general, a currency symbol should be accompanied by a numeric amount e.g. notHe converted hisUS$toA$butHe converted his US dollars to Australian dollarsorHe exchanged theUS$100note for Australian dollars.
  • Exceptions may occur in tables and infoboxes where space is limited e.g.Currencies accepted:US$,SFr,£,€.It may be appropriate to wikilink such uses, or add an explanatory note.

Currency conversions

• Conversions oflesser-known currenciesmay be provided in terms of more familiar currencies – such as the US dollar, euro or pound sterling – using an appropriate rate (which is oftennotthe current exchange rate). Conversions should be in parentheses after the original currency, along with the convert-to year; e.g.the grant in 2001 was 10,000,000Swedish kronor($1.4M, €970,000, or £850,000 as of 2009)
• Forobsolete currencies,provide an equivalent (formatted as a conversion) if possible, in the modern replacement currency (e.g. euros for amounts denominated infrancs), or a US-dollar equivalent where there is no modern equivalent.
• In some cases, it may be appropriate to provide a conversion accounting for inflation or deflation over time.See{{Inflation}}and{{Inflation-fn}}.
• When converting among currencies or inflating/deflating, it is rarely appropriate to give the converted amount to more than three significant figures; typically, only two significant figures are justified:the grant in 2001 was 10,000,000Swedish kronor($1.4M, €970,000, or £850,000),not($1,390,570, €971,673 or £848,646)

Common mathematical symbols

See also:Wikipedia:Manual of Style/MathematicsandHelp:Displaying a formula

• TheInsertmenu below the editing window gives a more complete list of math symbols, and allows symbols to be inserted without the HTML encoding (e.g.÷) shown here.
• Spaces are placed to left and right when a symbol is usedwith two operands(the sum 4 + 5), but no space is used whenthere is one operand(the value+5).Exception:spaces are usually omitted in inline fractions formed with/:3/4not3 / 4.
• The{{mvar}}(for single-letter variables) and{{math}}(for more complicated expressions) templates are available to display mathematical formulas in a manner distinct from surrounding text.
• The{{nbsp}}and{{nowrap}}templates may be used to prevent awkward linebreaks.

Common mathematical symbols

Symbol name	Example	Markup	Comments
Plus / positive	x+y	{{math|''x''+''y''}}
	+y	{{math|+''y''}}
Minus / negative	x−y	{{math|''x''−''y''}}	Do not use hyphens (-) or dashes ({{ndash}}or{{mdash}}).
	−y	{{math|−''y''}}
Plus-minus / minus-plus	41.5 ± 0.3	41.5±0.3
	−(±a) = ∓a	{{math|1=−(±''a'') =∓''a''}}
Multiplication, dot	x⋅y	{{math|''x''⋅''y''}}
Multiplication, cross	x×y	{{math|''x''×''y''}}	Do not use the letterxto indicate multiplication. However, anunspacedxmay be used as a substitute for "by" in common terms such as4x4.
Division,obelus	x÷y	{{math|''x''÷''y''}}
Equal / equals	x=y	{{math|1=''x''=''y''}}or {{math|''x''{{=}}''y''}}	Note the use of1=or{{=}}to make the template parameters work correctly
Not equal	x≠y	{{math|''x''≠''y''}}
Approx. equal	π≈ 3.14	{{math|''π''≈3.14}}
Less than	x<y	{{math|''x''&lt;''y''}}
Less or equal	x≤y	{{math|''x''&le;''y''}}
Greater than	x>y	{{math|''x''&gt;''y''}}
Greater or equal	x≥y	{{math|''x''&ge;''y''}}

Geographical coordinates

For draft guidance on, and examples of, coordinates for linear features, seeWikipedia:WikiProject Geographical coordinates/Linear.

Quick guide:

Quick how-to

To add57°18′22″N4°27′32″Wto the top of an article, use{{Coord}},thus:

{{Coord|57|18|22|N|4|27|32|W|display=title}}

Thesecoordinatesare indegrees,minutes, and seconds of arc.

"title" means that the coordinates will be displayed next to the article's title at the top of the page (in desktop view only; title coordinates do not display in mobile view) and before any other text or images. It also records the coordinates as the primary location of the page's subject in Wikipedia's geosearch API.

To add44.1124°N 87.9130°W/44.1124; -87.9130to the top of an article, use either

{{Coord|44.1124|N|87.9130|W|display=title}}

(which does not require minutes or seconds but does require the user to specify north/ south and east/west)or

{{Coord|44.1124|-87.9130|display=title}}

(in which the north and east are presumed by positive values while the south and west are negative ones). These coordinates are indecimal degrees.

• Degrees, minutes and seconds, when used, must each be separated by apipe ( "|" ).
• Map datummust beWGS84if possible (except for off-Earth bodies).
• Avoidexcessive precision(0.0001° is <11 m, 1″ is <31 m).
• Maintainconsistencyof decimal places or minutes/seconds between latitude and longitude.
• Latitude (N/S) must appear before longitude (E/W).

Optional coordinate parameters follow the longitude and are separated byan underscore ( "_" ):

• dim:dim:N(viewingdiameterinmetres)
• region:region:R(ISO 3166-1 Alpha -2orISO 3166-2code)
• type:type:T(landmarkorcity(30,000),for example)

Other optional parameters are separated bya pipe ( "|" ):

• display

  |display=inline(the default) to display in the body of the article only,

  |display=titleto display at the top of the article only (in desktop view only; title coordinates do not display in mobile view), or

  |display=inline,titleto display in both places.

• name

  name=Xto label the place on maps (default isPAGENAME)

Thus:{{Coord|44.1172|-87.9135|dim:30_region:US-WI_type:event

|display=inline,title|name=accident site}}

Use|display=title(or|display=inline,title) once per article, for the subject of the article, where appropriate.

• PerWP:ORDER,the template is placed at the bottom of the article in the 'end matter', after anynavigation templates,but before allcategories,including the{{DEFAULTSORT}}template. This template may also be placed within aninfobox,instead of at the bottom of the article.
• For full details, refer to{{Coord/doc}}.
• Additional guidance is available atobtaining coordinatesandconverting coordinates.

Geographical coordinateson Earth should be entered using a template to standardise the format and to provide a link to maps of the coordinates. As long as the templates are adhered to, a robot performs the functions automatically.

First,obtain the coordinates.Avoidexcessive precision.

The{{Coord}}template offers users a choice of display format throughuser styles,emits aGeo microformat,and is recognised (in thetitleposition) by the "nearby" feature of Wikipedia's mobile apps and by external service providers such as Google Maps and Google Earth, and Yahoo. Infoboxes automatically emit{{Coord}}.

The following formats are available.

• For degrees only (including decimal values):{{coord|dd|N/S|dd|E/W}}
• For degrees/minutes:{{coord|dd|mm|N/S|dd|mm|E/W}}
• For degrees/minutes/seconds:{{coord|dd|mm|ss|N/S|dd|mm|ss|E/W}}

where:

• dd,mm,ssare the degrees, minutes and seconds, respectively;
• N/Sis eitherNfor northern orSfor southernlatitudes;
• E/Wis eitherEfor eastern orWfor westernlongitudes;
• negative values may be used in lieu ofSandWto denote Southern and WesternHemispheres

For example:

For the city ofOslo,located at 59° 54′ 50″ N, 10° 45′ 8″ E:

{{coord|59|54|50|N|10|45|08|E}}– which becomes59°54′50″N10°45′08″E

For a country, likeBotswana,with no source on an exact geographic center, less precision is appropriate due to uncertainty:

{{coord|22|S|24|E}}– which becomes22°S24°E

Higher levels of precision are obtained by using seconds:

{{coord|33|56|24|N|118|24|00|W}}– which becomes33°56′24″N118°24′00″W

Coordinates can be entered as decimal values:

{{coord|33.94|S|118.40|W}}– which becomes33.94°S 118.40°W/-33.94; -118.40

Increasing or decreasing the number of decimal places controls the precision. Trailing zeros may be added as needed to give both values the same appearance.

Heathrow Airport,Amsterdam,Jan MayenandMount Bakerare examples of articles that contain geographical coordinates.

Generally, the larger the object being mapped, theless precisethe coordinates should be. For example, if just giving the location of a city, precision greater than degrees (°), minutes (′), seconds (″) is not needed, which suffice to locate, for example, the central administrative building. Specific buildings or other objects of similar size would justify precisions down to 10meters or even one meter in some cases (1″ ~15m to 30m, 0.0001° ~5.6m to 10m).

The final field, following the E/W, is available for attributes such astype:,region:,orscale:(the codes are documented atTemplate:Coord/doc § Coordinate parameters).

When adding coordinates, please remove the{{coord missing}}tag from the article, if present (often at the top or bottom).

For more information, seethe geographical coordinates WikiProject.

Templates other than{{coord}}should use the following variable names for coordinates:lat_d,lat_m,lat_s,lat_NS,long_d,long_m,long_s,long_EW.

See also

• Wikipedia:Date formattings
• m:Help:Date formatting featureat Meta
• m:Help:Calculation § Displaying numbers and numeric expressionsat Meta