Difference between revisions of "UniWiki:Manual of Style/Dates and numbers"

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This page is a part of the UniWiki's Manual of Style. It is a general guideline intended to harmonize article style across the UniWiki, though it is best treated with common sense, and exceptions may apply. Any substantive edit to this page should be approved by the Wiki Manager. When in doubt, discuss first on the talk page.

This page guides the presentation of numbers, dates, times, measurements, currencies and similar material in articles. Its aim is to promote clarity and cohesion; this is especially important Template:Em an article. The goal is to make the whole UniWiki easier and more intuitive to use.

Where this manual provides options, consistency should be maintained within an article unless there is a good reason to do otherwise. If discussion cannot determine which style to use in an article, defer to the style used by the first major contributor.

General notes

Quotations, titles, etc.

Quotations, titles of books and articles, and similar "imported" text should be faithfully reproduced, even if they employ 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.

It is acceptable to change other date formats in the same article to provide consistency, so long as those changes would otherwise be acceptable.

Non-breaking spaces

Guidance on the use of non-breaking spaces ("hard spaces") –  ,   – is given in some sections below. Not all situations in which hard spaces may be appropriate are described. For further information, see Wikipedia:Manual of Style § Controlling line breaks and Wikipedia:Line-break handling.

Chronological items

Statements likely to become outdated

See also: UniWiki:Manual of Style/Words to watch#Relative time references, and Wikipedia:As of

Except on pages updated regularly, terms such as now, currently, to date, so far, soon, and recently should usually be avoided in favor of phrases such as during the 1990s, since 2010, and in August 1969. For current and future events, use phrases like as of November 2024 or since the beginning of 2024 to signal the time-dependence of the information.

However, do not replace since the beginning of 2005 with as of 2005 because some information (the Template:Em of 2005) would be lost.

Relative-time expressions are acceptable for very long periods, such as geological epochs: Humans diverged from other primates long ago, but only recently developed state legislatures.

Time of day

Context determines whether the 12- or 24-hour clock is used; in both, colons separate hours, minutes and seconds (e.g. 1:38:09 pm or 13:38:09).

12-hour clock times end with dotted or undotted lower-case a.m. or p.m., or xtn|am or pm, preceded by a non-breaking space, e.g. 2:30 p.m. or 2:30 pm (markup: 2:30 p.m. or 2:30 pm), not 2:30p.m. or 2:30pm. Hours should not have a leading zero (e.g. 2:30 p.m., not 02:30 p.m.). Usually, use noon and midnight rather than 12 pm and 12 am; whether "midnight" refers to the start or the end of a date should be explicitly specified unless clear from the context.
24-hour clock times have no a.m., p.m., noon or midnight suffix. Hours under 10 should have a leading zero (e.g. 08:15). The time 00:00 refers to midnight at the start of a date, 12:00 to noon, and 24:00 to midnight at the end of a date, but 24 should not be used for the first hour of the next day (e.g. use 00:10 for ten minutes after midnight, not 24:10).

The numerical elements of times-of-day are figures (12:45 p.m.) rather than words (twelve forty-five p.m.) though conventional terms such as noon and midnight are acceptable (taking care, with the latter, to avoid possible date ambiguity in constructions such as midnight on July 17).

Time zones

Give dates and times appropriate to the time zone where an event took place. For example, the date of the attack on Pearl Harbor should be December 7, 1941 (Hawaii time/date). Give priority to the place at which the event had its most significant effects; for example, if a hacker based in China 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 in Coordinated Universal Time (UTC). For example:

• 8 p.m. Eastern Standard Time on January 15, 2001 (01:00 UTC, January 16)

Alternatively, include just the UTC offset:

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

Rarely, the time zone in which a historical event took place has since changed; for example, China to 1949 was divided into five time zones, whereas all of modern China is 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 the prime 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.

Dates, months and years

Formats

Acceptable date formats
General use	Only where brevity is helpful (refs, tables, infoboxes, etc.)	Comments
2 August 2001	2 Aug 2001
August 2, 2001	Aug 2, 2001	A comma follows the year unless followed by other punctuation:^[1] * The weather on March 12, 2005, was clear and warm * Everyone remembers July 21, 1969Template:Sndwhen man first landed on the Moon
2 August	2 Aug	Omit year only where there is no risk of ambiguity: * The 2012 London Olympics ran from 25 July to 12 August * January 1 is New Year's Day
August 2	Aug 2
No equivalent for general use	2001-08-02	Use `yyyy`-`mm`-`dd` format only with Gregorian dates from 1583 onward.^[2]
August 2001	Aug 2001

Dates should be linked only when they are germane to the subject.
For issues related to dates in sortable tables, see Wikipedia:Date sorting problems.
Phrases such as Fourth of July (or July Fourth, but not July 4th), Cinco de Mayo, Seventh of March Speech and Sete de Setembro are proper names, to which rules for dates do not apply (Any decent Fourth of July celebration includes fireworks).

Unacceptable date formats (except in external titles and quotes)
Unacceptable	Acceptable	Comments
Aug. 2	Aug 2	Do not add a dot to the day or to an abbreviated month
9. June	9 June or June 9	Do not add a dot to the day or to an abbreviated month
9 june june 9		Months are capitalized
9th June June 9th the 9th of June		Do not use ordinals (1st, 2nd, 3rd, etc.)
09 June June 09		Do not "zero-pad" month or day, except in all-numeric (`yyyy`-`mm`-`dd`) format
2007-4-15	2007-04-15
2007/04/15		Do not use separators other than hyphen
07-04-15		Do not abbreviate year to two digits
15-04-2007 04-15-2007		Do not use `dd`-`mm`-`yyyy`, `mm`-`dd`-`yyyy` or `yyyy`-`dd`-`mm` formats, as they are ambiguous for some dates^[3]
7/2001 7-2001 07-2001 2001-07 2001 July July of 2001	July 2001	Do not use these formats.
July, 2001	July 2001	No comma between month and year
3 July, 2001	3 July 2001	No comma between month and year
July 3 2001	July 3, 2001	Comma required between day and year
the '97 elections the 97 elections	the 1997 elections	Do not abbreviate year
Two thousand one	2001	Years and days of the month are not normally written in words
the first of May May the first	May 1 or 1 May
June 0622	June 622	Do not zero-pad years
sold in the year 1995	sold in 1995	Use "in the year" only where needed for clarity (About 1800 ships arrived in the year 1801)

Consistency

Dates in article body text should all use the same format: She fell ill on 25 June 2005 and died on 28 June, but not She fell ill on 25 June 2005 and died on June 28.

Retaining existing format

See also: UniWiki:Manual of Style#Retaining existing styles

If an article has evolved using predominantly one format, the whole article should conform to it, unless there are reasons for changing it based on strong national ties to the topic or consensus on the article's talk page.
The date format chosen by the first major contributor in the early stages of an article should continue to be used, unless there is reason to change it based on strong national ties to the topic 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".

Gregorian and New Eden calendars

Dates on the UniWiki must be given in the appropriate calendar based on the context of the date or event they are associated with. A date can be given in the Gregorian calendar, the New Eden calendar, or both, as described below. For example, an article on the early Amarr Empire will only give dates in the New Eden calendar, while an article about the Purity of the Throne event may give dates in both calendars.

Real-world events are dated using the Gregorian calendar.
In-game events that correspond to real-world dates (such as the Yoiul Festival 2016) or that are the result of player actions are dated using the New Eden calendar when discussing the event in an in-universe context, and using the Gregorian calendar when discussing the event in a real-world or meta context.
All other in-game events or lore concepts are dated using the New Eden calendar.

Ranges

Use a dash, or a word such as from or between, but not both: from 1881 to 1886 (not from 1881–1886); between June 1 and July 3 (not between June 1Template:SndJuly 3)
A simple year–year range is written using an en dash (–) not a hyphen or slash; this dash is usually Template:Em (that is, with no space on either side); and the range's end year is usually given in full:

• 1881–1886; 1881–1992 (not 1881–86; 1881Template:Snd1992)

Markup: 1881{{ndash}}1886 or 1881–1886

Two-digit ending years (1881–82, but never 1881–882 or 1881–2) may be used in the case of two consecutive years; in infoboxes and tables where space is limited (using a single format consistently in any given table column); or in certain topic areas if there is a very good reason, such as matching the established convention of reliable sources.
The slash 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 an Template:Em en dash as well:

day–day: 5–7 January 1979; January 5–7, 1979; elections were held March 5–8
month–month: the 1940 peak period was May–July; the peak period was May–July 1940; (but the peak period was May 1940Template:SndJuly 1940 uses a Template:Em en dash; see below.

If at least one of the items on either side of the en dash contains a space, then a Template:Em en dash ({{snd}}) is used:

between specific dates in different months: They travelled June 3Template:SndAugust 18, 1952; They travelled 3 JuneTemplate:Snd18 August 1952
between dates in different years:

Charles Robert Darwin (12 February 1809Template:Snd19 April 1882) was an English naturalist ...

Markup: 12{{nbsp}}February 1809{{snd}}19{{nbsp}}April 1882 or 12 February 1809 – 19 April 1882

Abraham Lincoln (February 12, 1809Template:SndApril 15, 1865) was the 16th President of ...

between months in different years: The exception was in force August 1892Template:SndJanuary 1903; The Ghent Incursion (March 1822Template:SndJanuary 1, 1823) was ended by the New Year's Treaty

Markup: March 1822{{snd}}January{{nbsp}}1, 1823 or March 1822 – January 1, 1823

Where circa or other modifiers are used: reigned c. 1393Template:Snd1414 See § Uncertain, incomplete, or approximate dates, below.

Constructions such as 1982–present (with unspaced ndash), January 1, 2011Template:Sndpresent (spaced ndash), or January 2011Template:Sndpresent (spaced ndash) may be used where appropriate, but other constructions may be more appropriate in prose (see § Statements likely to become outdated). In tables and infoboxes where space is limited, pres. may be used (1982–pres.). Do not use incomplete-looking constructions such as 1982– and 1982–... .
For a person still living: Serena Williams (born September 26, 1981) is a ..., not (September 26, 1981Template:Snd) or (born on September 26, 1981).

Do not use * to indicate born; use b. only where space is limited e.g. tables and infoboxes; use either born or b. consistently in any given table column.

Where birthdate is unknown: John Smith (died May 1, 1622) ... or John Smith (died 1622) ...

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

An overnight period may be expressed using a slash between two contiguous dates: the night raids of 30/31 May 1942 or raids of 31 May / 1 June 1942.

Or use an en dash: (unspaced) raids of 30–31 May 1942; (spaced) raids of 31 MayTemplate:Snd1 June 1942.

Uncertain, incomplete, or approximate dates

To indicate "around", "approximately", or "about", the use of the spaced, unitalicised form c. 1291 is preferred over circa, ca, ca., approximately, or approx.:

• At the birth of Roger Bacon (c. 1214) ...

Where both endpoints of a range are approximate, c. should appear before each date:

• Dionysius Exiguus (c. 470Template:Sndc. 540) ... (not Dionysius Exiguus (c. 470Template:Snd540) ...)

• Rameses III (reigned c. 1180 – c. 1150 BCE) ... (not Rameses III (reigned c. 1180Template:Snd1150 BCE) ...)

When a date is known to be either of two years (e.g. from a regnal or AH year 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: April 14, 1224 (unattested date). Do not use a question mark (1291?), because it fails to communicate the nature of the uncertainty.
Ranges in which c., after, fl. or similar forms appear—whether on one or both sides—employ a spaced endash ({{snd}}) and ideally a nonbreaking space should follow very short modifiers such as c. and fl.. Markup: 1896{{snd}}after 1954

Other

Days of the week

Days of the week are capitalized (Sunday, Wednesday).

Seasons

Seasons are uncapitalized (a hot summer) except when personified: Old Man Winter's bleak greys relent as Spring begins to show her colors.
All seasons used should refer to seasons in the northern hemisphere, as that is where CCP is located, and is thus the reference point for game development, patch releases, and other events.
- In the rare case where an article references seasons in relation to a specific country or region not in the northern hemisphere, the appropriate season for that location may be used.

Numbers

Numbers as figures or words

See also information on specific situations, elsewhere in this guideline.

Generally, in article text:

Integers from zero to nine are spelled out in words.
Integers greater than nine Template:Em may be expressed either in numerals or in words (16 or sixteen, 84 or eighty-four, 200 or two hundred). Numbers between 21 and 99 are hyphenated (including when part of a larger number): fifty-six or fifty-six thousand but five hundred or five thousand.
Other numbers are given in numerals (3.75, 544) or in forms such as 21 million. Markup: 21{{nbsp}}million

"billion" and "trillion" are understood to represent their short-scale values of 10⁹ (1,000,000,000) and 10¹² (1,000,000,000,000), respectively. Keep this in mind when using material from non-English sources.
M (unspaced) or bn (unspaced) respectively may be used for "million" or "billion" after a number, when the word has been spelled out at the first occurrence (She received £70 million and her son £10M).
SI prefixes and symbols, such as mega- (M), giga- (G) and tera- (T), should be used only with units of measure as appropriate to the field, and not to express large quantities in other contexts (of the population of 1.3G people, 300 megadeaths would be expected).

Notes and exceptions:

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 < 22/7, not three < π < 22 sevenths).
Comparable quantities should be all spelled out or all in figures:

• five cats and thirty-two dogs, not five cats and 32 dogs

• 86 men and 103 women, not eighty-six men and 103 women

• There were 3 winners and 206 losers, even though 3 would normally be given as three; or Three won and two hundred six lost (or two hundred and six in British English), even though two hundred six would normally be given as 206); but not There were three winners and 206 losers.

But adjacent quantities not comparable should usually be in Template:Em twelve 90-minute volumes or 12 ninety-minute volumes, not 12 90-minute volumes or twelve ninety-minute volumes.

Avoid awkward juxtapositions: On February 25, 2011, twenty-one more were chosen, not On February 25, 2011, 21 more were chosen.

Personal ages are typically stated in figures (8-year-old child) except for large, approximate values (69-million-year-old fossil).
Sometimes figures and words carry different meanings; for example Every locker except one was searched implies there is a single exception (without specifying which), while Every locker except 1 was searched means that only locker number 1 was not searched.
Proper names, technical terms, and the like are never altered: Seven Samurai; The Sixth Sense; 5 Channel Street; Channel 5; Chanel No. 5; Fourth Estate; The Third Man; Second Judicial District; First Amendment; Zero Hour!; Less Than Zero

Avoid beginning a sentence with figures:

• Not There were many matches. 23 ended in a draw,

but There were many matches; 23 ended in a draw or There were many matches. Twenty-three ended in a draw.

• Not 1945 and 1950 saw crucial elections (nor Nineteen forty-five and 1950 saw crucial electionsTemplate:Sndbecause comparable numbers should be both written in words or both in figures) but The elections of 1945 and 1950 were crucial.

Exception: Where a proper name, technical term, etc., itself beginning with a numeral, opens the sentence (1-Naphthylamine is typically synthesized via the Feldenshlager–Glockenspiel process) although this can usually be avoided by rewording (Feldenshlager–Glockenspiel is the process typically used in the synthesis of 1-naphthylamine).

Ordinals

Ordinal suffixes (-st, -nd, -rd, -th) are not superscripted (123rd and 496th, not 123^rd nor 496^th).
For guidance on choosing between e.g. 15th and fifteenth, see § Numbers as figures or words.
Regnal numbers are normally written with Roman numerals (without suffix, e.g. Elizabeth II not Elizabeth IInd).
Do not use a dot (.) or the ordinal mark (º) to indicate ordinals.

Singular versus plural

Nouns following simple fractions are singular (He took ¹⁄₄ dose; net change in score was −¹⁄₂ point; ³⁄₂ dose).
Nouns following mixed numbers are plural (suicide victim knew even 1¹⁄₂ doses could be fatal; continued another 4³⁄₄ miles).
Nouns following the lone, unsigned digit 1 are singular, but those following other decimal numbers (i.e. base-10 numbers not involving fractions) are plural (increased 0.7 percentage points; 365.25 days; paid 5 dollars per work hour, 1 dollar per travel hour, 0 dollars per standby hour; increased by 1 point but net change +1 points; net change −1 points; net change 1.0 points).
The same rules apply to numbers given in words (one dose; one and one-half doses; zero dollars; net change negative one points).

Fractions and ratios

Spelled-out fractions are hyphenated: seven-eighths.
Where numerator and denominator can each be expressed in one word, a fraction is usually spelled out (e.g. a two-thirds majority; moved one-quarter mile); use figures if a fraction appears with a symbol (e.g. ¹⁄₄ miTemplate:Sndmarkup: 1&frasl;4 mi, not a quarter of a mi or one-quarter mi).
Mixed numbers are usually given in figures, unspaced (not Fellini's film 8 ¹⁄₂ or 8-¹⁄₂ but Fellini's film 8¹⁄₂Template:Sndmarkup: 81&frasl;2). In any case the integer and fractional parts should be consistent (not nine and ¹⁄₂).
Metric (SI) measurements generally use decimals, not fractions (5.25 mm, not 5¹⁄₄ mm).
Do not use special characters such as "½" (deprecated markup: ~~½~~ or ~~½~~).
Ordinal suffixes such as -th should not be used with fractions expressed in figures (not each US state has 1/50th of the Senate's votes; 1/8th mile, but one-fiftieth of the Senate's votes; 1/8 mile; one-eighth mile).
Dimensionless ratios (i.e. those not incorporating units) are given using numerals and a colon, or numbers-as-words and to: favored by a 3:1 ratio or a three-to-one ratio, but not a 3/1 ratio or a 3–1 ratio. Use a "spaced" colon when a decimal point is present (a 3.5 : 1 ratioTemplate:Sndmarkup: a 3.5 : 1 ratio). Do not use the colon form where units are involved (dissolve using a 3 ml:1 g ratio)—instead see ratios section of table at § Unit names and symbols, below.

Decimals

A period/full point (.), Template:Em a comma, is used as the decimal point (6.57, not 6,57).
Numbers between −1 and +1 require a leading zero (0.02, not .02); exceptions are sporting performance averages (.430 batting average) and commonly used terms such as .22 caliber.
Indicate repeating digits with an overbar e.g. 14.3128 gives 14.3128. (Consider explaining this notation on first use.) Do not write e.g. 14.31(28) because it resembles notations for § Uncertainty and rounding.

Grouping of digits

Digits should be grouped and separated by commas, (Template:Em a 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, 255,200 km, 8,274,527th, ¹⁄_86,400).
Numbers with exactly four digits left of the decimal point may optionally be grouped (either 1,250 or 1250), provided that this is consistent within each article.
When commas are used left of the decimal point, digits right of the decimal point are not grouped (i.e. should be given as an unbroken string).

Delimiting style should be consistent throughout a given 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.

An exception is made for four-digit page numbers or four-digit calendar years. These should never be grouped (not sailed in 1,492, though dynasty collapsed around 10,400 BC).

Percentages

In the body of non-scientific/non-technical articles, percent (American English) or per cent (British English) are commonly used: 10 percent; ten percent; 4.5 per cent. Ranges are written ten to twelve per cent or ten to twelve percent, not ten–twelve per cent or ten to twelve %.
In the body of scientific/technical articles, and in Template:Em of any article, the symbol % (unspaced) is more common: 71%, not 71 % or three %. Ranges: 10–12%, not 10%–12% or 10 to 12%.
When expressing the difference between two percentages, do not confuse a percentage change with a change in percentage points.

Scientific notation

Scientific notation always has a single nonzero digit to the left of the point: not 60.22 × 10²², but 6.022 × 10²³.
In a table column (or other presentation) in which all values can be expressed with a single power of 10, consider giving e.g. × 10⁷ once in the column header, and omitting it in the individual entries. (Markup:  × 107)
The number of digits indicates the precision. For example, 5 × 10³ means rounded to the nearest thousand; 5.0 × 10³ to the nearest hundred; 5.00 × 10³ to the nearest ten; and 5.000 × 10³ to the nearest unit.

Uncertainty and rounding

Where explicit uncertainty information (such as a margin of error) is available and appropriate for inclusion, it may be written in various ways:

• (1.534 ± 0.035) × 10²³ m

• 12.34 m² ± 5% (not used with scientific notation)

• 1.604(48) × 10⁻⁴ J (equivalent to (1.604 ± 0.048) × 10⁻⁴ J)^[4]

• Polls estimated Jones's share of the vote would be 55 percent, give or take about 3 percent

Where explicit Template:Em (or is unimportant for the article's purposes) round to an appropriate number of significant 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 299,792,458 m/s

Template:Em Particle velocities eventually reached almost two-thirds the 300-million-metre-per-second speed of light.

• The city's 1920 population was 10,000 (not population was 9,996Template:Sndan official figure unlikely to be accurate at full precision)

Template:Em The 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 population figure is helpful to readers)

• The accident killed 337 passengers and crew, and three airport workers (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)

Template:Em Officials 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 $8.5 million ... (where the actual figure was $8,462,247.63) ...Template:Sndreduced on appeal 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, not 41 and 47.4 percent), unless different precisions are actually intended.
It may sometimes be appropriate to note the Template:Em of 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 publish information on the uncertainty of this estimate

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 inchesTemplate:Sndheights are conventionally reported only to the nearest inch, even though greater precision may be available in principle)

Template:Em The 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) can further emphasize its approximate nature.

Non-base-10 notations

In computer-related articles, use the prefix 0x for hexadecimal, 0 for octal, and 0b for binary, unless there is a strong reason to use some other notation.^[5] Explain these prefixes in the article's introduction or on first use.
In all other articles, use  to create subscripts: 137₉, 201₃. Markup: 1379, 2013
For bases above 10, use symbols conventional for that base (e.g. for base 16 use 0–9 and A–F.

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 kilometers (120 mi).

In all articles, the primary units chosen will be SI units, non-SI units officially accepted for use with the SI, or such other units as they appear in-game.

Unit names and symbols

Template:Em

Examples of unit names: foot, meter, kilometer.
Examples of unit 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 250 kg).

Exception: Certain units are generally represented by their symbols (e.g. °C rather than degrees Celsius) even on first use, though their unit names may be used for emphasis or clarity (automatic conversion of degrees Celsius to degrees Fahrenheit).
Exception: Consider using inches (but not in.) in place of in where the latter might be misread as a prepositionTemplate:Mdashbbut not where the value is followed by a parenthesized conversion e.g. bolts 5 in (12.7 cm) long, or is part of such a conversion (bolts 12.7 cm (5 in) 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 were originally 2.3 megaelectronvolts (MeV), but were eventually 6 MeV).
Ranges use unspaced en dash (Template:Tlx) if only one unit symbol is used at the end (e.g. 5.9–6.3 kg), and spaced en dash (Template:Tlx) if two symbols are used (e.g. 3 μmTemplate:Snd1 mm); 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 (e.g. Template:Nobr, Template:Nobr, Template:Nobr and Template:Nobr are all acceptable).
Length–width, length–width–height and similar dimensions may be separated by the multiplication sign (× or ×) or the word Template:Xtn.
- With the multiplication sign, each number should be followed by a unit name or symbol (if appropriate):

• 1 m × 3 m × 6 m, not Template:Nobr, (1 × 3 × 6) m nor Template:Nobr

• a metal plate 1 ft × 3 ft × 0.25 in

• a railroad easement 10 ft × 2.5 mi

With Template:Xtn, the unit need be given only once: Template:Nobr or Template:Nobr
The unspaced letter x may be used in common terms such as 4x4.

General guidelines on unit names and symbols
Aspect	Guideline	Acceptable	Unacceptable
Unit names and symbols	Except as listed in the "Specific units" table below, unit Template:Em are uncapiTemplate:Shytal Template:Shyized 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.^[6]	8 kg 100 kPa	8 Kg 100 kpa
	Unit symbols are undotted.	38 cm of rope	38 cm. of rope
	Unit Template:Em are given in lower case except: where any word would be capitalTemplate:Shyized, or where otherwise specified in the SI brochure^[7] or this Manual of Style.Template:Clarify	He walked several miles. Miles of trenches were dug.	A Gallon equals 4 Quarts.
	The spelling of certain unit names (some of which are listed in § Specific units, below) varies with the variety of English followed by the article.
	Write unit names and symbols in upright ([[Roman type\|Template:Sic]]) type, except where emphasizing in context.	10 m 29 kilograms	10 Template:Em 29 Template:Em
		Thus each two-liter jug contained only two Template:Em.
Numeric values	Do not spell out numbers before unit Template:Em ...	12 min	twelve min
	... but words Template:Em figures may be used with unit Template:Em.	twelve minutes 12 minutes
	Values with no accompanying unit are usually given in figures.	Set the pointer to 5.	Set the pointer to five.
	Use a nonbreaking space ({{nbsp}} or ` `) between a number and a unit Template:Em, or use {{nowrap}} ...	29 kg (markup: `29 kg` or Template:Nowr)	29kg
	... though with certain symbols no space is used (see "Specific units" table below) ...	Template:Nobr	Template:Nobr
	... a normal space is used between a number and a unit Template:Em.	29 kilograms (markup: `29 kilograms`)
	To form a value and a unit Template:Em into 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 unit Template:Em.	a blade 10 cm long	a 10-cm blade
Plurals	SI unit Template:Em are pluralized by adding the appropriate -s or -es suffix ...	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
	Some non-SI units have irregular plurals.	1 foot; 10 feet	10 foots
	Some non-SI units have irregular plurals.	1 stratum; 10 strata (unusual)	10 stratums
	Unit Template:Em (in any system) are identical in singular and plural.	Template:Nobr Template:Nobr Template:Nobr	Template:Nobr
Powers	Format exponents using <sup>, not special characters.	km² (markup: `km<sup>2</sup>`)	km² (`km²`)
	Or use Template:Xtn or Template:Xtn (Template:Em the unit being modified).	ten metres per second squared	ten metres per squared second
	For areas or volumes only, Template:Xtn or Template:Xtn may be used (Template:Em the unit being modified).	ten metres per second squared	ten metres per square second
		tons per square mile
	Template:Xtn or Template:Xtn may be used with US customary or imperial units, but not with SI units.	15 sq mi 3 cu ft	15 sq km 3 cu m
Products	Indicate a product of unit Template:Em with either a hyphen or a space.	foot-pound foot pound	footpound foot·pound
	Indicate a product of unit Template:Em with `·` or ` ` (Template:Em Template:Tlx is not equivalent to `·`.)	ms = millisecond m·s or m s = metre-second
	Template:Em In some topic areas such as power engineerTemplate:Shying, certain products take neither space nor `·`. Follow the practice of reliable sources in the article's topic area.	Wh, VA, Ah kWh, MVA, GAh
	To pluralize a product of unit Template:Em, pluralize only the final unit. (Unit Template:Em are never pluralized.)	ten foot-pounds	ten feet-pounds
Ratios, Rates, Densities	Indicate a ratio of unit Template:Em with Template:Xtn.	meter per second	meter/second
	Indicate a ratio of unit Template:Em with a forward slash (`/`), followed by either a single symbol or a parenthesized product of symbolsTemplate:Snddo 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 unit Template:Em, pluralize only the numerator unit. (Unit Template:Em are never pluralized.)	Template:Nowrap 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 = pounds per 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.	25 kilopascals	25 kilo pascals 25 kilo-pascals
	Prefixes are added without contraction, except as shown here:	kilohm megohm hectare	kiloohm megaohm hectoare
	The Template:Xtn, Template:Xtn, Template:Xtn, and Template:Xtn prefixes should generally be avoided; exceptions include centimetre, decibel, hectolitre, hectare, and hectopascal.	100 metres 0.1 km	1 hectometre
	Do not use M for 10³, MM for 10⁶, or B for 10⁹ (except as noted elsewhere on this page for Template:Xtn and Template:Xtn, 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	Template:Nobr 1 footTemplate:Hsp, 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 1:30Template:Thinsp^{[note 1]} Template:Nobr Template:NobrTemplate:Thinsp^{[note 2]}	Template:Nobr Template:Nobr Template:Nobr
	... but are not normally used in SI.	1.33 m 133 cm	1 m 33 cm

Template:Em

^ Only use this format if it is clear from the context whether this means hours and minutes (H:MM) or minutes and seconds (M:SS).
^ This format is used in astronomy (see the IAU Style Manual^[8] for details).

Specific units

The following table lists only units that need special attention.
The SI Brochure^[7] should be consulted for guidance on use of other SI and non-SI units.

Guidelines on specific units
Group	Name	Symbol	Comment
Length, Speed	inch	in	Do not use `′` (′), `″` (″), apostrophe (') or quote (").
	foot	ft	Do not use `′` (′), `″` (″), apostrophe (') or quote (").
	foot per second	ft/s (Template:Em fps)
	hand	h or hh	Equal to 4 inches; used in measurement of horses. A dot may be followed by additional inches e.g. Template:Nobr indicates Template:Nobr
	knot	kn (Template:Em kt or kN)
	metre meter Template:Em	m
	micron	μm (Template:Em μ)	Markup: `μm` Link to micrometre (for which micron is a synonym) on first use.
	astronomical unit	AU Template:Nobr	Template:Xtn is the most commonly used unit symbol for the astronomical unit, both in popular and professional astronomical articles, and is hence also used on Wikipedia, although some organizations, including the BIPM^[7] and IAU,^[9] recommend Template:Xtn.
	mile	mi	In nautical and aeronautical contexts use statute mile rather than mile to avoid confusion with nautical mile.
	mile per hour	mph
	nautical mile	Template:Nobr
Volume, Flow	cubic centimetre Template:Nobr	cm³	Markup: `cm<sup>3</sup>`
	cubic centimetre Template:Nobr	cc	Non-SI symbol used for certain engine displacements; link to Cubic centimetre on first use.
	imperial fluid ounce	imp fl oz	Template:Xtn or Template:Xtn (or Template:Xtn) must be specified; Template:Xtn or Template:Xtn must be specified for fluid ounces and US units, except with gallon. (Without Template:Xtn, ounce is ambiguousTemplate:Sndversus avoirdupois ounce or troy ounceTemplate:Sndand US pint or US quart are ambiguousTemplate:Sndversus US dry pint or US dry quart.)
	imperial pint	imp pt
	imperial quart	imp qt
	imperial gallon	imp gal
	US fluid ounce	US fl oz
	US fluid pint	US fl pt
	US fluid quart	US fl qt
	US gallon	US gal
	cubic foot	cu ft (Template:Em cf)	Write five million cubic feet, 5,000,000 cu ft or Template:Val, not 5 MCF.
	Template:Nobr	cu ft/s (Template:Em cfs)
	litre liter Template:Em	l or L	The symbol l ("el") in isolation (i.e. not in such forms as ml) is easily mistaken for the digit 1 or the capital letter I ("eye").
Mass, Force, Density, Pressure	long ton	long ton	Spell out in full.
	short ton	short ton	Spell out in full.
	Template:Nobr	psi
	tonne metric ton Template:Em	t Template:Nobr
	troy ounce	oz t	Template:Xtn or Template:Xtn must be specified. Articles about precious metals, black powder, and gemstones should always specify whether ounces and pounds are avoirdupois or troy.
	troy pound	lb t
	carat	carat	Used to express masses of gemstones and pearls.
Purity	carat or karat	k or Kt	A measure of purity for gold alloys. (Do not confuse with the unit of mass with the same spelling.)
Time	second	s	Do not use `′` (′), `″` (″), apostrophe (') or quote (") for minutes or seconds. See also the hours–minutes–seconds formats for time durations described in the Unit names and symbols table.
	minute	min
	hour	h
	year	a	Use Template:Xtn only with an SI prefix multiplier (a rock formation 540 Ma old, not Life expectancy rose to 60 a).
	year	y or yr	Template:Crossref
Information, Data	bit	bit Template:Nobr	Template:Crossref Do not confuse bit/second or byte/second with baud (Bd).
	byte	Template:Nobr
	bit per second	bit/s (Template:Em bps, b/s)
	byte per second	B/s or byte/s Template:Nobr
Angle
	arcminute	′	Markup: `′` (prime ′ not apostrophe/single quote '). Template:Nobr
	arcsecond	″	Markup: `″` (double prime ″ not double-quote "). Template:Nobr
	degree	°	Markup: `°` (degree ° not masculine ordinal º or ring Template:Thinsp̊Template:Hsp). Template:Nobr
Temperature	degree	°	Markup: `°`. Use a nonbreaking space: Template:Nobr, not Template:Nobr nor Template:Nobr
	degree Celsius Template:Nobr	°C (Template:Em C)
	kelvin Template:Nobr	K (Template:Em °K)
Energy	calorie small calorie gram calorie	cal	In certain subject areas, calorie is conventionTemplate:Shyally 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 to SI units (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 therefore also a kilogram calorie.
Energy	kilocalorie large calorie kilogram calorie (Template:Em CalorieTemplate:Snd Template:Nobr	kcal

Quantities of bytes and bits

Template:Shortcut In quantities of bits and bytes, the prefixes Template:Xtn (symbol Template:Xtn or Template:Xtn), Template:Xtn (Template:Xtn), Template:Xtn (Template:Xtn), Template:Xtn (Template:Xtn), etc., are ambiguous. They may be based on a decimal system (like the standard SI prefixes), meaning 10³, 10⁶, 10⁹, 10¹², etc., or they 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 as RAM), while the decimal meanings are more common for data transmission rates, disk storage and in theoretical calculations in modern academic textbooks. Template:Bit and byte prefixes Follow these recommendations when using these prefixes in Wikipedia articles:

Following the SI standard, a lower-case k should be used for "kilo-" whenever it means 1000 in computing contexts, whereas a capital K should 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, use Ki instead).
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 (Template:Tlx 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 on hard 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 64 MB (Template:Nowrap video card and a 100 GB Template:Nowrap hard drive

• A 64 MB (67,108,864-byte) video card and a 100 GB (100,000,000,000-byte) hard drive

Avoid inconsistent combinations such as A 64 MB (67,108,864-byte) video card and a 100 GB Template:Nowrap hard drive. Footnotes, such as those seen in Template:Nowrap, may be used for disambiguation.
Unless explicitly stated otherwise, one byte is eight bits Template:Crossref.

The IEC prefixes Template:Xtn (symbol Template:Xtn), Template:Xtn (Template:Xtn), Template:Xtn (Template:Xtn), etc., are generally not to be used except:^[10]

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

Template:Shortcut

See also: Wikipedia:WikiProject Numismatics/Style#Article titles

Choice of currency

In country-specific articles, such as Economy of Australia, use the currency of the subject country.
In non-country-specific articles such as Wealth, use US dollars ($123), euros (€123), or pounds sterling (£123).

Currency names

Do not capitalize the names or denominations of currencies, currency subdivisions, coins and banknotes: not a Five-Dollar bill, four Quarters, and one Penny total six Dollars one Cent but a 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 as Australian dollar.
To pluralize Template:Xtn use the standard English plurals (ten euros and fifty cents), not the invariant 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 (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. Template:Em

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 countriesTemplate:Snd Template:Crossref) use the full signifier (e.g. US$, A$) each time, except (possibly) where a particular context makes this both unnecessary and undesirable.
In articles entirely on EU-, UK- and/or US-related topics, all occurrences may be shortened (€26, £22 or $34), unless this would be unclear.

The pound sterling is represented by the £ symbol, with one horizontal bar. The double-barred ₤ symbol is ambiguous, as it has also been used for the Italian lira and other currencies. For non-British currencies that use pounds or a pound symbol (e.g. the Irish pound, IR£) use the symbol conventionally preferred for that currency.
If there is no common English abbreviation or symbol, follow the ISO 4217 standard. Template:Crossref

Formatting

A period (full stop, .) is used as the decimal pointTemplate:Sndnever a comma ($6.57, not $6,57).
Template:Crossref
Do not place a currency symbol Template:Em the accompanying numeric figures (e.g. 123$, 123£, 123€) unless that is the normal convention for that symbol when writing in English: smaller British coins include 1p, 2p, and 5p denominations. Never use forms such as $US123 or $123 (US).
Currency abbreviations that come before the numeric value are Template:Em if they consist of a nonalphabetic symbol only, or end in a symbol (£123; €123); but Template:Em if alphabetic (R 75).
Ranges should be expressed giving the currency signifier just once: $250–300, not $250–$300.
million and billion should be spelled out on first use, and (optionally) abbreviated M or bn (both unspaced) thereafter: She received £70 million and her son £10M; the school's share was $250–300 million, and the charity's $400–450M.
In general, a currency symbol should be accompanied by a numeric amount e.g. not He converted his US$ to A$ but He converted his US dollars to Australian dollars or He exchanged the US$100 note for Australian dollars.

Exceptions may occur in tables and infoboxes where space is limited e.g. Currencies accepted for deposit: US$, SFr, GB£, €. It may be appropriate to wikilink such uses, or add an explanatory note.

Conversions

Conversions of Template:Em may be provided in terms of more familiar currenciesTemplate:Sndsuch as the US dollar, euro or pound sterlingTemplate:Sndusing an appropriate rate (which is often Template:Em the current exchange rate). Conversions should be in parentheses after the original currency, rounding to avoid false precision (two significant digits is usually sufficient, as most exchange rates fluctuate significantly), with at least the year given as a rough point of conversion rate reference; e.g. Since 2001 the grant has been 10,000,000 Swedish kronor ($1.4M, €1.0M, or £800k Template:As of), not ($1,390,570, €971,673 or £848,646).
For Template:Em, provide an equivalent (formatted as a conversion) if possible, in the modern replacement currency (e.g. decimal pounds for historical pre-decimal pounds-and-shillings), 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. Template:Crossref

Common mathematical symbols