The liter (spelled liter in American English and litre in Commonwealth English) is a unit of volume. There are two official symbols, the Latin letter el in both cases: l and L. The liter is not an SI unit but is accepted for use with the SI. The SI unit of volume is the cubic metre (m³). American English (AmE) is the dialect of the English language used mostly in the United States of America. ... Commonwealth English is a collective term for the perceived standard English language used in the Commonwealth of Nations1, applying in theory to Australian English, British English, Caribbean English, Canadian English, Hiberno-English (Irish English)2, Hong Kong English3, Indian English (includes Pakistani English), formal Malaysian English, New Zealand English, formal... Volume, also called capacity, is a quantification of how much space an object occupies. ... L is the twelfth letter of the Latin alphabet. ... Cover of brochure The International System of Units. ... The cubic meter (symbol m³) is the SI derived unit of volume. ...

Definitions and equivalents

A liter is defined as a special name for a cubic decimeter (1 L = 1 dm³).

• 1 L = 1000 cm³ (exactly)
• 1000 L = 1 m³ (exactly)

SI prefixes applied to the liter

The liter may be used with some SI prefixes. An SI prefix is a prefix that can be applied to an SI unit to form a decimal multiple or submultiple. ...

Name origin

The word "liter" is derived from an older French unit, the litron, whose name came from Greek via Latin. This article needs to be cleaned up to conform to a higher standard of quality. ...

Other common metric equivalencies

• 1 µL (microliter) = 1 mm³ (cubic millimeter)
• 1 mL (milliliter) = 1 cm³ (cubic centimeter)

Conversions

One liter

≈ 0.87987699 Imperial quart

Inverse: One Imperial quart ≡ 1.1365225 litres

≈ 1.056688 US fluid quarts

Inverse: One US fluid quart ≡ 0.946352946 litres

≈ 0.0353146667 cubic foot

Inverse: One cubic foot ≡ 28.316846592 litres

A quart is a unit of measurement for volume. ...

Explanation

Liters are most commonly used for items measured by the capacity or size of their container (such as fluids and berries), whereas cubic meters (and derived units) are most commonly used for items measured either by their dimensions or their displacements. The liter is often also used in some calculated measurements, such as density (kg/L), allowing an easy comparison with the density of water.

One liter of water weighs almost exactly one kilogram. Similarly: 1 mL of water weighs about 1 g; 1000 liters of water weighs about 1000 kg (1 tonne). This relationship is due to the history of the unit but since 1964 has not been part of the definition. The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ...

Symbol

Originally, the only symbol for the liter was l (lowercase letter l), following the SI convention that only those unit symbols that abbreviate the name of a person start with a capital letter. Cover of brochure The International System of Units. ...

In many English-speaking countries, the most common shape of a handwritten Arabic digit 1 is just a vertical stroke, that is it lacks the upstroke added in many other cultures. Therefore, the digit 1 may easily be confused with the letter l. On some typewriters, particularly older ones, the l key had to be used to type the numeral 1. Further, in some typefaces the two characters are nearly indistinguishable. This caused some concern, especially in the medical community. As a result, L (uppercase letter L) was accepted as an alternative symbol for liter in 1979. The United States National Institute of Standards and Technology now recommends the use of the uppercase letter L, a practice that is also widely followed in Canada and Australia. In these countries, the symbol L is also used with prefixes, as in mL and µL, instead of the traditional ml and µl used in Europe. Arabic numerals (also called Hindu numerals or Hindu-Arabic numerals) are by far the most common form of symbolism used to represent numbers. ... This page refers to the year 1979. ... The National Institute of Standards and Technology (or NIST) formerly known as The National Bureau of Standards is a non regulatory agency of the United States Department of Commerce’s Technology Administration. ...

Prior to 1979, the symbol ℓ (script small l, U+2113), came into common use in some countries; for example, it was recommended by South African Bureau of Standards publication M33 in the 1970s. This symbol can still be encountered occasionally in some English-speaking countries, but it is not used in most countries and not officially recognised by the BIPM, the International Organization for Standardization, or any national standards body. Technical note: Due to technical limitations, some web browsers may not display some special characters in this article. ... The Bureau International des Poids et Mesures (International Bureau of Weights and Measures, or BIPM) is a standards organization, one of the three organizations established to maintain the SI system under the terms of the Metre Convention. ... Logo of the International Organization for Standardization The International Organization for Standardization (ISO) is an international standard-setting body composed of representatives from national standards bodies. ...

History

In 1793, the liter was introduced in France as one of the new "Republican Measures", and defined as one cubic decimeter.

In 1879, the CIPM adopted the definition of the liter, and the symbol l (lowercase letter l). The International Committee for Weights and Measures is the English name of the Comité international des poids et mesures (CIPM, sometimes written in English Comité International des Poids et Mesures). ...

In 1901, at the 3rd CGPM conference, the liter was redefined as the space occupied by 1 kg of pure water at the temperature of its maximum density (3.98 °C) under a pressure of 1 atm. This made the liter equal to about 1.000 028 dm³ (earlier reference works usually put it at 1.000 027 dm³). The General Conference on Weights and Measures is the English name of the Conférence générale des poids et mesures (CGPM, sometimes written in English Conférence Générale des Poids et Mesures). ... A girl in a swimming pool full of water Water (from the Old English waeter; c. ... diurnal (daily) rhythm of air pressure in northern Germany (black curve is air pressure) Atmospheric pressure is the pressure above any area in the Earths atmosphere caused by the weight of air. ...

In 1964, at the 12th CGPM conference, the original definition was reverted to thus the liter was once again defined in exact relation to the meter, as another name for the cubic decimeter, that is, exactly 1 dm³. NIST Reference The General Conference on Weights and Measures is the English name of the Conférence générale des poids et mesures (CGPM, sometimes written in English Conférence Générale des Poids et Mesures). ...

In 1979, at the 16th CGPM conference, the alternative symbol L (uppercase letter L) was adopted. It also expressed a preference that in the future only one of these two symbols should be retained, but in 1990 said it was still too early to do so. The General Conference on Weights and Measures is the English name of the Conférence générale des poids et mesures (CGPM, sometimes written in English Conférence Générale des Poids et Mesures). ...

See also

• Claude Émile Jean-Baptiste Litre
• Pint
• Gallon
• Kilogram
• Cubic metre

Claude Émile Jean-Baptiste Litre is a fictional character created in 1978 by Kenneth Woolner of the University of Waterloo in order to justify the use of a capital L to denote litres. ... The pint is a unit of volume. ... The gallon (abbr. ... The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ... The cubic meter (symbol m³) is the SI derived unit of volume. ...

External links

• BIPM's "SI Brochure"
• BIPM's "(Table 6 -) Non-SI units accepted for use with the International System"
• NIST note on SI units
• NIST recommends uppercase letter L
• UK National physical laboratory's "Internationally recognised non SI units" page