Wikivoyage:Measurements

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We often have to use measurements in Wikivoyage—for the distances between places, for the altitude of mountains, for the temperature of deserts, for the volume of a glass of beer. This style guideline gives some suggestions for how to specify and format measurements, their units and unit abbreviations.

Note: The abbreviations below are bolded for clarity of exposition, but abbreviations in Wikivoyage articles shouldn't be bolded just because they're abbreviations!

Use local units of measurement[edit]

When showing a measurement, use the local system of units for the destination you're describing. This is the system that travelers will see on road signs, local maps, menus, food packages, weather reports, etc.

For almost all of the world, this is the metric system. For the United States of America, it's the U.S. system of units—similar to, but certainly not the same as, the imperial system of the United Kingdom. In some cases, the systems are mixed—for example, in the United Kingdom, road distances are measured in miles and beer served by the pint, while meat and canned goods, for example, are measured in (kilo)grams. Milk is measured in both pints (in England and Wales) and litres (in Scotland). Wikivoyage needs both accuracy and consistency.

The chief difference between the U.S. system of units and the imperial system is in the sizes of the pint and the gallon. The U.S. measures are 20% smaller than the imperial measures. That means you get more drunk on a British pint, and you get fewer miles to the gallon on American roads!

For articles that don't deal with a particular destination (like travel topics), use metric along with U.S. or imperial measures when needed or originally specified (e.g.: "No more than 3 oz of liquids or gels may be taken through airport security in the U.S.").

Provide conversions[edit]

It's easier for travelers to understand measurements if they're converted to their own system—so try to provide conversions for measurements into both the metric (SI) and U.S. styles.

If the preferred units are metric, try to provide U.S. Standard measurements in parentheses. If the preferred units are U.S. Standard, try to provide metric measurements in parentheses. If for some reason the local unit is neither metric nor US, try to provide first metric, then U.S. (separated by a comma) enclosed in the same parentheses afterwards.

Don't repeat conversions unnecessarily and if you provide a conversion, use only the same number of significant digits as the original measure (these measurements are going to be used by travelers, not scientists).

Avoid orphaned units[edit]

Except for measurements of temperature and voltage, we have a mild preference for separating the number from its associated unit by a single space, but:

  • Don't go wild copy editing different formatting (unless you're seriously underemployed)
  • To avoid the unit of measurement that "belongs" to a measurement being "orphaned" from its associated unit when it wraps to a following line, separate the pair with a non breaking space character " " rather than a simple space, eg: "4500 km" will display 4500 km. You can also use the template nowrap to achieve the same, eg: {{nowrap|4500 km}}

Periods and commas[edit]

Since this is the English language version of Wikivoyage, a full stop or period should be used separating any decimal fraction of a number and never a comma, whatever the local practice is.

For similar reasons, never use a full stop or period as the delimiter to separate groups of three numerals left of the decimal point. Use a comma for this purpose instead.

Examples[edit]

The following are some examples of good practice for measurements.

However, consider if you can make the prose just as clear to a traveler, while avoiding unit conversions.

  • Nightime winters temperatures in Canberra can drop below freezing, but snow is rare.
  • The walk to the lake will take around 30 mins and involves climbing around 30 stairs.

Area[edit]

Always abbreviate units in listings. Do not put periods (full stops) after units. Never use an "s" after a unit abbreviation to make it plural. Don't capitalize the first letter of any of the base units below.

  • square metre =
  • square kilometre = km²
  • hectare = ha
  • square foot = ft²
  • square yard = yd²
  • square mile = mi²
  • acre = acre

Duration[edit]

Always abbreviate units in listings. Do not put periods (full stops) after units. Never use an "s" after a unit abbreviation to make it plural. Never capitalize the first letter.

  • year = yr
  • week = wk
  • hour = hr
  • minute = min

Electrical[edit]

  • alternating current = AC
  • direct current = DC
  • ampere(s) or amp(s) = A
  • volt(s) = V
  • cycles per second = Hz

Length[edit]

Always abbreviate metric units in listings. Do not put periods (full stops) after units. Never use an "s" after a unit abbreviation to make it plural. Don't capitalize the first letter of any of the base units below.

  • kilometre = km
  • metre = m
  • centimetre = cm
  • millimetre = mm
  • mile = mi
  • yard = yd
  • foot = ft
  • inch = in

Do not use quotation marks (' or ") to signify feet or inches; that would confuse some readers.

Spell nautical miles in full, because some abbreviations, including "nm", conflict with abbreviations for other units.

Speed[edit]

Show as km/h or mph

e.g.: "The latest Boeing 787 Dreamliner has a cruising speed of Mach 0.85 (913 km/h, 567 mph) at 10,700 m (35,000 ft)"

Temperature[edit]

Always abbreviate units in listings.

  • Celsius = degrees Celsius or °C (Don't use "centigrade".)
  • Fahrenheit = degrees Fahrenheit or °F

When referring to places inside the United States, show temperatures in Fahrenheit first followed by Celsius in parentheses. Anywhere else, use Celsius first with Fahrenheit in parentheses.

If the prolix prose form is not chosen, temperature ranges should be shown in this form: -3°C to 26°C (rather than "-3°C - 26°C" or "-3°- 26°C")

Once you choose a temperature format, use that format throughout the article. Do not switch back and forth.

Volume[edit]

Always abbreviate units in listings. Do not put periods (full stops) after units. Never use an "s" after a unit abbreviation to make it plural. Don't capitalize the first letter of any of the base unit abbreviations below (except for the litre = L).

Dry volume[edit]

  • cubic metre =
  • cubic centimetre = cm³, or equivalently ml
  • cubic foot = ft³ or cu ft
  • cubic yard = yd³ or cu yd

Fluid volume[edit]

  • litre = L
  • millilitre = mL

(In order to avoid confusion with the numeral 1 and letter l, L is always capitalized when used as an abbreviation for litre.)

  • pint = pt
  • quart = qt
  • gallon = gal

Weight/mass[edit]

Always abbreviate units in listings. Do not put periods (full stops) after units. Never use an "s" after a unit abbreviation to make it plural. Don't capitalize the first letter of any of the base units below.

  • metric tonne (1000 kg—also: tonne) = t
  • kilogram = kg
  • gram = g
  • milligram = mg
  • short ton (2000 lb) = ton
  • pound = lb
  • ounce = oz