Litre
Encyclopedia
The litre is a metric system
unit of volume
equal to 1 cubic decimetre
(dm3), to 1,000 cubic centimetres (cm3), and to 1/1,000 cubic metre
. The unit has two SI
unit symbols: the Latin
letter L
in lower and upper case (l and L). If the lower case L is used, it is sometimes rendered as a cursive
ℓ to help distinguish it from the capital "I", although this usage has no official approval by any international bureau.
The word litre is derived from an older French
unit, the litron, whose name came from Greek
via Latin. The original French metric system
used the litre as a base unit, and it has been used in several subsequent versions of the metric system
and is accepted for use with the SI, although not an official SI unit
— the SI unit of volume is the cubic metre
(m3). The spelling of the word used by the International Bureau of Weights and Measures
is "litre" and this is also the usual one in most English-speaking countries, but in American English
the spelling is "liter", being endorsed by the United States.
One litre of liquid water has a mass
of almost exactly one kilogram
, due to the gram being defined in 1795 as one cubic centimetre of water.
or 10 centimetres x 10 centimetres x 10 centimetres, (1 L ≡ 1 dm3≡ 1000 cm3). Hence 1 L ≡ 0.001 m3
≡ 1000 cm3
, and 1 m3 (i.e. a cubic metre, which is the S.I. unit for volume) is exactly 1000 L.
From 1901 to 1964, the litre was defined as the volume of one kilogram of pure water
at 4 °C
and 760 millimetres of mercury
pressure. During this time, a litre was about 1.000028 dm3. In 1964 this definition was abandoned in favour of the current one.
s and berries) which are measured by the capacity or size of their container, whereas cubic metres (and derived units) are most commonly used for items measured either by their dimensions or their displacements. The litre is often also used in some calculated measurements, such as density (kg/L), allowing an easy comparison with the density of water.
One litre of water has a mass
of almost exactly one kilogram
when measured at its maximal density, which occurs at about 4 °C. Similarly: 1 millilitre of water has a mass of about 1 g; 1,000 litres of water has about 1000 kg of mass. This relationship holds because the gram was originally defined as the mass of 1 mL of water; however, this definition was abandoned in 1799 because the density of water changes with temperature and, very slightly, with pressure.
We now know that density also depends on the isotopic ratios of the oxygen and hydrogen atoms in a particular water sample. Modern measurements of Vienna Standard Mean Ocean Water, which is pure distilled water with an isotopic
composition representative of the average of the world’s oceans, show it has a density of at its point of maximum density (3.984 °C) under one standard atmosphere (760 torr
) of pressure.
es. The most commonly used derived unit is the millilitre, defined as one-thousandth of a litre, and also often referred to by the SI derived unit name "cubic centimetre
". It is a commonly used measure, especially in medicine and cooking. Other units may be found in the table below, where the more often used terms are in bold. However, some authorities advise against some of them; for example, in the United States, NIST advocates using the millilitre or litre instead of the centilitre.
for its volume relative to the imperial pint is "a litre of water is a pint and three quarters".
A litre is the volume of a cube with sides of 10 cm, which is slightly less than a cube of sides 4 inches (or one-third of a foot). One cubic foot would contain exactly 27 such cubes (four inches on each side), making one cubic foot approximately equal to 27 litres. One cubic foot has an exact volume of 28.316846592 litres, which is within 5% of the 27-litre approximation.
A litre of water has a mass almost exactly equal to one kilogram
of water. An early definition of the kilogram was set as the mass of one litre of water. Because volume changes with temperature and pressure, and pressure uses units of mass, the definition of a kilogram was changed. At standard pressure, one litre of water has a mass of 0.999975 kg at , and 0.997 kg at .
convention that only those unit symbols that abbreviate the name of a person start with a capital letter.
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. Further, on some typewriter
s, particularly older ones, the unshifted L key had to be used to type the numeral 1. Even in some computer typefaces, the two characters are barely distinguishable. This caused some concern, especially in the medical community. As a result, L (uppercase letter L) was adopted as an alternative symbol for litre 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. In the UK
and Ireland
as well as the rest of Europe, lowercase l is used with prefixes, though whole litres are often written in full (so, "750 ml" on a wine bottle, but often "1 litre" on a juice carton).
Some style manuals, including the Publication Manual of the American Psychological Association, require a combination of the two styles of abbreviation. APA style mandates that the symbol L be used when indicating whole litres. When indicating a fraction of a litre, APA requires the use of the lowercase l.
Prior to 1979, the symbol (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 and Canada in the 1970s. This symbol can still be encountered occasionally in some English-speaking countries, and its use is ubiquitous in Japan and South Korea. Fonts covering the CJK characters usually include not only the script small l but also four precomposed characters: ㎕, ㎖, ㎗, and ㎘ (U+3395 to U+3398) for the microlitre, millilitre, decilitre, and kilolitre. Nevertheless, it is no longer used in most countries and was never officially recognised by the BIPM or the International Organization for Standardization
, and is a character often not available in currently used documentation systems.
in 1795 as one of the new "republican units of measurement" and defined as one cubic decimetre. The original decimetre length was 44.344 lignes, which was revised in 1798 to 44.3296 lignes. This made the original litre 1.000974 of today's dm3. It was against this litre that the kilogram was constructed.
In 1879, the CIPM adopted the definition of the litre, with the symbol l (lowercase letter L).
In 1901, at the 3rd CGPM
conference, the litre 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 litre equal to about 1.000 028 dm3 (earlier reference works usually put it at 1.000 027 dm3).
In 1964, at the 12th CGPM
conference, the original definition was reverted to, and thus the litre was once again defined in exact relation to the metre, as another name for the cubic decimetre, that is, exactly 1 dm3.
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.
with the colloquial term "mil", which is intended to mean "one thousandth of a metre", or in the United States
, a thousandth of an inch. This generally does not create confusion because the context is usually sufficient — one being a volume, the other a linear measurement.
The abbreviation cc (for cubic centimetre
, equal to a millilitre or mL) is a unit of the cgs system, that preceded the MKS system
, that later evolved into the SI
system. The abbreviation cc is still commonly used in many fields including medical dosage and sizing for small combustion engine
displacement
, such as those used in motorcycles.
In European countries where the metric system
was established well before the adoption of the SI
standard, there is still carry-over of usage from the precursor cgs and MKS systems. In the SI
system, use of prefixes for powers of 1,000 is preferred and all other multiples discouraged. However, in countries where these other multiples were already established, their use remains common. In particular, use of the centi (10−2), deci (10−1), deca (10+1), and hecto (10+2) prefixes are still common. For example, in many European countries, the hectolitre is the typical unit for production and export volumes of beverages (milk, beer, soft drinks, wine, etc.) and for measuring the size of the catch and quotas for fishing boats; decilitres are common in Switzerland
and Scandinavia
and sometimes found in cookbooks; centilitres indicate the capacity of drinking glasses and of small bottles. In colloquial Dutch
in Belgium
, a 'vijfentwintiger' and a 'drieëndertiger' (literally 'twenty-fiver' and 'thirty-threer') are the common beer glasses, the corresponding bottles mention 25 cL or 33 cL. Bottles may also be 75 cL or half size at 37.5 cL for 'artisanal' brews or 70 cL for wines or spirits. Cans come in 25 cL, 33 cL and 50 cL aka 0.5 L. Family size bottles as for soft drinks or drinking water use the litre (0.5 L, 1 L, 1.5 L, 2 L) as well as beer barrels (50 L or the half-sized 25 L). This unit is most common for all other household size containers of liquids from thermocans to buckets to bath tubs; as well as for fuel
tanks and consumption for heating or by vehicles.
In countries where the metric system was adopted as the official measuring system after the SI
standard was established, common usage more closely follow contemporary SI
conventions. For example, in Canada
, where the metric system is now in widespread use, consumer beverages are labelled almost exclusively using litres and millilitres. Hectolitres sometimes appear in industry, but centilitres and decilitres are rarely, if ever, used. Larger volumes are usually given in cubic metres (equivalent to 1 kL), or thousands or millions of cubic metres. The situation is similar in Australia
, although kilolitres, megalitres, and gigalitres are commonly used for measuring water consumption, reservoir capacities and river flows.
For larger volumes of fluids, such as annual consumption of tap water, lorry (truck) tanks, or swimming pools, the cubic metre
is the general unit. It is also generally for all volumes of a non-liquid nature.
Fluid flow rates may be measured in litres per unit time interval (second, minute, hour, etc.).
Metric system
The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...
unit of volume
Volume
Volume is the quantity of three-dimensional space enclosed by some closed boundary, for example, the space that a substance or shape occupies or contains....
equal to 1 cubic decimetre
Decimetre
A decimetre is a unit of length in the metric system, equal to one tenth of a metre, the SI base unit of length. In simple words there are 10 cm in a decimetre....
(dm3), to 1,000 cubic centimetres (cm3), and to 1/1,000 cubic metre
Cubic metre
The cubic metre is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère...
. The unit has two SI
Si
Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
unit symbols: the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
letter L
L
Ł or ł, described in English as L with stroke, is a letter of the Polish, Kashubian, Sorbian, Łacinka , Łatynka , Wilamowicean, Navajo, Dene Suline, Inupiaq, Zuni, Hupa, and Dogrib alphabets, several proposed alphabets for the Venetian language, and the ISO 11940 romanization of the Thai alphabet...
in lower and upper case (l and L). If the lower case L is used, it is sometimes rendered as a cursive
Cursive
Cursive, also known as joined-up writing, joint writing, or running writing, is any style of handwriting in which the symbols of the language are written in a simplified and/or flowing manner, generally for the purpose of making writing easier or faster...
ℓ to help distinguish it from the capital "I", although this usage has no official approval by any international bureau.
The word litre is derived from an older French
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
unit, the litron, whose name came from Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
via Latin. The original French metric system
Metric system
The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...
used the litre as a base unit, and it has been used in several subsequent versions of the metric system
Metric system
The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...
and is accepted for use with the SI, although not an official SI unit
International System of Units
The International System of Units is the modern form of the metric system and is generally a system of units of measurement devised around seven base units and the convenience of the number ten. The older metric system included several groups of units...
— the SI unit of volume is the cubic metre
Cubic metre
The cubic metre is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère...
(m3). The spelling of the word used by the International Bureau of Weights and Measures
International Bureau of Weights and Measures
The International Bureau of Weights and Measures , is an international standards organisation, one of three such organisations established to maintain the International System of Units under the terms of the Metre Convention...
is "litre" and this is also the usual one in most English-speaking countries, but in American English
American English
American English is a set of dialects of the English language used mostly in the United States. Approximately two-thirds of the world's native speakers of English live in the United States....
the spelling is "liter", being endorsed by the United States.
One litre of liquid water has a mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
of almost exactly one kilogram
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...
, due to the gram being defined in 1795 as one cubic centimetre of water.
Definition
A litre is defined as a special name for a cubic decimetreDecimetre
A decimetre is a unit of length in the metric system, equal to one tenth of a metre, the SI base unit of length. In simple words there are 10 cm in a decimetre....
or 10 centimetres x 10 centimetres x 10 centimetres, (1 L ≡ 1 dm3≡ 1000 cm3). Hence 1 L ≡ 0.001 m3
Cubic metre
The cubic metre is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère...
≡ 1000 cm3
Cubic centimetre
A cubic centimetre is a commonly used unit of volume extending the derived SI-unit cubic metre, and corresponds to the volume of a cube measuring 1 cm × 1 cm × 1 cm...
, and 1 m3 (i.e. a cubic metre, which is the S.I. unit for volume) is exactly 1000 L.
From 1901 to 1964, the litre was defined as the volume of one kilogram of pure water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
at 4 °C
Celsius
Celsius is a scale and unit of measurement for temperature. It is named after the Swedish astronomer Anders Celsius , who developed a similar temperature scale two years before his death...
and 760 millimetres of mercury
Torr
The torr is a non-SI unit of pressure with the ratio of 760 to 1 standard atmosphere, chosen to be roughly equal to the fluid pressure exerted by a millimetre of mercury, i.e., a pressure of 1 torr is approximately equal to 1 mmHg...
pressure. During this time, a litre was about 1.000028 dm3. In 1964 this definition was abandoned in favour of the current one.
Explanation
Litres are most commonly used for items (such as fluidFluid
In physics, a fluid is a substance that continually deforms under an applied shear stress. Fluids are a subset of the phases of matter and include liquids, gases, plasmas and, to some extent, plastic solids....
s and berries) which are measured by the capacity or size of their container, whereas cubic metres (and derived units) are most commonly used for items measured either by their dimensions or their displacements. The litre is often also used in some calculated measurements, such as density (kg/L), allowing an easy comparison with the density of water.
One litre of water has a mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
of almost exactly one kilogram
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...
when measured at its maximal density, which occurs at about 4 °C. Similarly: 1 millilitre of water has a mass of about 1 g; 1,000 litres of water has about 1000 kg of mass. This relationship holds because the gram was originally defined as the mass of 1 mL of water; however, this definition was abandoned in 1799 because the density of water changes with temperature and, very slightly, with pressure.
We now know that density also depends on the isotopic ratios of the oxygen and hydrogen atoms in a particular water sample. Modern measurements of Vienna Standard Mean Ocean Water, which is pure distilled water with an isotopic
Isotope
Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons. Atoms of a particular element by definition must contain the same number of protons but may have a distinct number of neutrons which differs from atom to atom, without changing the designation...
composition representative of the average of the world’s oceans, show it has a density of at its point of maximum density (3.984 °C) under one standard atmosphere (760 torr
Torr
The torr is a non-SI unit of pressure with the ratio of 760 to 1 standard atmosphere, chosen to be roughly equal to the fluid pressure exerted by a millimetre of mercury, i.e., a pressure of 1 torr is approximately equal to 1 mmHg...
) of pressure.
SI prefixes applied to the litre
The litre, though not an official SI unit, may be used with SI prefixSI prefix
The International System of Units specifies a set of unit prefixes known as SI prefixes or metric prefixes. An SI prefix is a name that precedes a basic unit of measure to indicate a decadic multiple or fraction of the unit. Each prefix has a unique symbol that is prepended to the unit symbol...
es. The most commonly used derived unit is the millilitre, defined as one-thousandth of a litre, and also often referred to by the SI derived unit name "cubic centimetre
Cubic centimetre
A cubic centimetre is a commonly used unit of volume extending the derived SI-unit cubic metre, and corresponds to the volume of a cube measuring 1 cm × 1 cm × 1 cm...
". It is a commonly used measure, especially in medicine and cooking. Other units may be found in the table below, where the more often used terms are in bold. However, some authorities advise against some of them; for example, in the United States, NIST advocates using the millilitre or litre instead of the centilitre.
| Multiple | Name | Symbols | Equivalent volume | Submultiple | Name | Symbols | Equivalent volume | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 100 L | litre | l (ℓ) | L | dm3 | cubic decimetre | |||||||
| 101 L | decalitre | dal | daL | 101 dm3 | ten cubic decimetres | 10−1 L | decilitre | dl | dL | 102 cm3 | hundred cubic centimetres | |
| 102 L | hectolitre | hl | hL | 102 dm3 | hundred cubic decimetres | 10−2 L | centilitre | cl | cL | 101 cm3 | ten cubic centimetres | |
| 103 L | kilolitre | kl | kL | m3 | cubic metre | 10−3 L | millilitre | ml | mL | cm3 | cubic centimetre | |
| 106 L | megalitre | Ml | ML | dam3 | cubic decametre | 10−6 L | microlitre | µl | µL | mm3 | cubic millimetre | |
| 109 L | gigalitre | Gl | GL | hm3 | cubic hectometre | 10−9 L | nanolitre | nl | nL | 106 µm3 | million cubic micrometres | |
| 1012 L | teralitre | Tl | TL | km3 | cubic kilometre | 10−12 L | picolitre | pl | pL | 103 µm3 | thousand cubic micrometres | |
| 1015 L | petalitre | Pl | PL | 103 km3 | thousand cubic kilometres | 10−15 L | femtolitre | fl | fL | µm3 | cubic micrometre | |
| 1018 L | exalitre | El | EL | 106 km3 | million cubic kilometres | 10−18 L | attolitre | al | aL | 106 nm3 | million cubic nanometres | |
| 1021 L | zettalitre | Zl | ZL | Mm3 | cubic megametre | 10−21 L | zeptolitre | zl | zL | 103 nm3 | thousand cubic nanometres | |
| 1024 L | yottalitre | Yl | YL | 103 Mm3 | thousand cubic megametres | 10−24 L | yoctolitre | yl | yL | nm3 | cubic nanometre | |
Non-metric conversions
| Metric Unit |
Approximate Value |
Non-Metric Unit |
System |
Non-Metric Unit |
Metric Equivalency |
|---|---|---|---|---|---|
| 1 L | ≈ 0.87987699 | quart Quart The quart is a unit of volume equal to a quarter of a gallon, two pints, or four cups. Since gallons of various sizes have historically been in use, quarts of various sizes have also existed; see gallon for further discussion. Three of these kinds of quarts remain in current use, all approximately... |
Imperial | 1 quart | ≡ 1.1365225 L |
| 1 L | ≈ 1.056688 | fluid quarts | U.S. | 1 fluid quart | ≡ 0.946352946 L |
| 1 L | ≈ 1.75975326 | pint Pint The pint is a unit of volume or capacity that was once used across much of Europe with values varying from state to state from less than half a litre to over one litre. Within continental Europe, the pint was replaced with the metric system during the nineteenth century... s |
Imperial | 1 pint | ≡ 0.56826125 L |
| 1 L | ≈ 2.11337641 | fluid pints | U.S. | 1 fluid pint | ≡ 0.473176473 L |
| 1 L | ≈ 0.2641720523 | liquid gallon Gallon The gallon is a measure of volume. Historically it has had many different definitions, but there are three definitions in current use: the imperial gallon which is used in the United Kingdom and semi-officially within Canada, the United States liquid gallon and the lesser used United States dry... |
U.S. | 1 liquid gallon | ≡ 3.785411784 L |
| 1 L | ≈ 0.21997 | gallon | Imperial | 1 gallon | ≡ 4.54609 L |
| 1 L | ≈ 0.0353146667 | cubic foot Cubic foot The cubic foot is an Imperial and US customary unit of volume, used in the United States and the United Kingdom. It is defined as the volume of a cube with sides of one foot in length.-Conversions:- Symbols :... |
1 cubic foot | ≡ 28.316846592 L | |
| 1 L | ≈ 61.0237441 | cubic inch Cubic inch The cubic inch is a unit of measurement for volume in the Imperial units and United States customary units systems. It is the volume of a cube with each of its 3 sides being one inch long.... es |
1 cubic inch | ≡ 0.016387064 L | |
| 1 L | ≈ 33.8140 | customary fluid ounce Fluid ounce A fluid ounce is a unit of volume equal to about 28.4 mL in the imperial system or about 29.6 mL in the US system. The fluid ounce is distinct from the ounce, which measures mass... s |
U.S. | 1 customary fluid ounce | ≡ 29.5735295625 mL |
| 1 L | ≈ 35.1950 | fluid ounce Fluid ounce A fluid ounce is a unit of volume equal to about 28.4 mL in the imperial system or about 29.6 mL in the US system. The fluid ounce is distinct from the ounce, which measures mass... s |
Imperial | 1 fluid ounce | ≡ 28.4130625 mL |
Rough conversions
One litre is slightly more than one U.S. liquid quart and slightly less than one imperial quart or one U.S. dry quart. A mnemonicMnemonic
A mnemonic , or mnemonic device, is any learning technique that aids memory. To improve long term memory, mnemonic systems are used to make memorization easier. Commonly encountered mnemonics are often verbal, such as a very short poem or a special word used to help a person remember something,...
for its volume relative to the imperial pint is "a litre of water is a pint and three quarters".
A litre is the volume of a cube with sides of 10 cm, which is slightly less than a cube of sides 4 inches (or one-third of a foot). One cubic foot would contain exactly 27 such cubes (four inches on each side), making one cubic foot approximately equal to 27 litres. One cubic foot has an exact volume of 28.316846592 litres, which is within 5% of the 27-litre approximation.
A litre of water has a mass almost exactly equal to one kilogram
Kilogram
The kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...
of water. An early definition of the kilogram was set as the mass of one litre of water. Because volume changes with temperature and pressure, and pressure uses units of mass, the definition of a kilogram was changed. At standard pressure, one litre of water has a mass of 0.999975 kg at , and 0.997 kg at .
Symbol
Originally, the only symbol for the litre was l (lowercase letter L), following the SISi
Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
convention that only those unit symbols that abbreviate the name of a person start with a capital letter.
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. Further, on some typewriter
Typewriter
A typewriter is a mechanical or electromechanical device with keys that, when pressed, cause characters to be printed on a medium, usually paper. Typically one character is printed per keypress, and the machine prints the characters by making ink impressions of type elements similar to the pieces...
s, particularly older ones, the unshifted L key had to be used to type the numeral 1. Even in some computer typefaces, the two characters are barely distinguishable. This caused some concern, especially in the medical community. As a result, L (uppercase letter L) was adopted as an alternative symbol for litre in 1979. The United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
National Institute of Standards and Technology
National Institute of Standards and Technology
The National Institute of Standards and Technology , known between 1901 and 1988 as the National Bureau of Standards , is a measurement standards laboratory, otherwise known as a National Metrological Institute , which is a non-regulatory agency of the United States Department of Commerce...
now recommends the use of the uppercase letter L, a practice that is also widely followed in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
and Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. 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. In the UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
and Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
as well as the rest of Europe, lowercase l is used with prefixes, though whole litres are often written in full (so, "750 ml" on a wine bottle, but often "1 litre" on a juice carton).
Some style manuals, including the Publication Manual of the American Psychological Association, require a combination of the two styles of abbreviation. APA style mandates that the symbol L be used when indicating whole litres. When indicating a fraction of a litre, APA requires the use of the lowercase l.
Prior to 1979, the symbol (script small l, U
Unicode
Unicode is a computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems...
+2113), came into common use in some countries; for example, it was recommended by South African Bureau of Standards
South African Bureau of Standards
The South African Bureau of Standards is a South African statutory body that was established in terms of the Standards Act, 1945 and continues to operate in terms of the latest edition of the Standards Act, 2008 The South African Bureau of Standards (SABS) is a South African statutory body that...
publication M33 and Canada in the 1970s. This symbol can still be encountered occasionally in some English-speaking countries, and its use is ubiquitous in Japan and South Korea. Fonts covering the CJK characters usually include not only the script small l but also four precomposed characters: ㎕, ㎖, ㎗, and ㎘ (U+3395 to U+3398) for the microlitre, millilitre, decilitre, and kilolitre. Nevertheless, it is no longer used in most countries and was never officially recognised by the BIPM or the International Organization for Standardization
International Organization for Standardization
The International Organization for Standardization , widely known as ISO, is an international standard-setting body composed of representatives from various national standards organizations. Founded on February 23, 1947, the organization promulgates worldwide proprietary, industrial and commercial...
, and is a character often not available in currently used documentation systems.
History
The litre was introduced in FranceFrance
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
in 1795 as one of the new "republican units of measurement" and defined as one cubic decimetre. The original decimetre length was 44.344 lignes, which was revised in 1798 to 44.3296 lignes. This made the original litre 1.000974 of today's dm3. It was against this litre that the kilogram was constructed.
In 1879, the CIPM adopted the definition of the litre, with the symbol l (lowercase letter L).
In 1901, at the 3rd CGPM
General Conference on Weights and Measures
The General Conference on Weights and Measures is the English name of the Conférence générale des poids et mesures . It is one of the three organizations established to maintain the International System of Units under the terms of the Convention du Mètre of 1875...
conference, the litre was redefined as the space occupied by 1 kg of pure water
Water
Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...
at the temperature of its maximum density (3.98 °C) under a pressure of 1 atm. This made the litre equal to about 1.000 028 dm3 (earlier reference works usually put it at 1.000 027 dm3).
In 1964, at the 12th CGPM
General Conference on Weights and Measures
The General Conference on Weights and Measures is the English name of the Conférence générale des poids et mesures . It is one of the three organizations established to maintain the International System of Units under the terms of the Convention du Mètre of 1875...
conference, the original definition was reverted to, and thus the litre was once again defined in exact relation to the metre, as another name for the cubic decimetre, that is, exactly 1 dm3.
In 1979, at the 16th CGPM
General Conference on Weights and Measures
The General Conference on Weights and Measures is the English name of the Conférence générale des poids et mesures . It is one of the three organizations established to maintain the International System of Units under the terms of the Convention du Mètre of 1875...
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.
Colloquial and practical usage
In spoken English, the abbreviation "mL" (for millilitre) is often pronounced as "mil", homophonousHomophone
A homophone is a word that is pronounced the same as another word but differs in meaning. The words may be spelled the same, such as rose and rose , or differently, such as carat, caret, and carrot, or to, two, and too. Homophones that are spelled the same are also both homographs and homonyms...
with the colloquial term "mil", which is intended to mean "one thousandth of a metre", or in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, a thousandth of an inch. This generally does not create confusion because the context is usually sufficient — one being a volume, the other a linear measurement.
The abbreviation cc (for cubic centimetre
Cubic centimetre
A cubic centimetre is a commonly used unit of volume extending the derived SI-unit cubic metre, and corresponds to the volume of a cube measuring 1 cm × 1 cm × 1 cm...
, equal to a millilitre or mL) is a unit of the cgs system, that preceded the MKS system
Mks system of units
The MKS system of units is a physical system of units that expresses any given measurement using fundamental units of the metre, kilogram, and/or second ....
, that later evolved into the SI
Si
Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
system. The abbreviation cc is still commonly used in many fields including medical dosage and sizing for small combustion engine
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...
displacement
Engine displacement
Engine displacement is the volume swept by all the pistons inside the cylinders of an internal combustion engine in a single movement from top dead centre to bottom dead centre . It is commonly specified in cubic centimeters , litres , or cubic inches...
, such as those used in motorcycles.
In European countries where the metric system
Metric system
The metric system is an international decimalised system of measurement. France was first to adopt a metric system, in 1799, and a metric system is now the official system of measurement, used in almost every country in the world...
was established well before the adoption of the SI
Si
Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
standard, there is still carry-over of usage from the precursor cgs and MKS systems. In the SI
Si
Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
system, use of prefixes for powers of 1,000 is preferred and all other multiples discouraged. However, in countries where these other multiples were already established, their use remains common. In particular, use of the centi (10−2), deci (10−1), deca (10+1), and hecto (10+2) prefixes are still common. For example, in many European countries, the hectolitre is the typical unit for production and export volumes of beverages (milk, beer, soft drinks, wine, etc.) and for measuring the size of the catch and quotas for fishing boats; decilitres are common in Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
and Scandinavia
Scandinavia
Scandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...
and sometimes found in cookbooks; centilitres indicate the capacity of drinking glasses and of small bottles. In colloquial Dutch
Dutch language
Dutch is a West Germanic language and the native language of the majority of the population of the Netherlands, Belgium, and Suriname, the three member states of the Dutch Language Union. Most speakers live in the European Union, where it is a first language for about 23 million and a second...
in Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
, a 'vijfentwintiger' and a 'drieëndertiger' (literally 'twenty-fiver' and 'thirty-threer') are the common beer glasses, the corresponding bottles mention 25 cL or 33 cL. Bottles may also be 75 cL or half size at 37.5 cL for 'artisanal' brews or 70 cL for wines or spirits. Cans come in 25 cL, 33 cL and 50 cL aka 0.5 L. Family size bottles as for soft drinks or drinking water use the litre (0.5 L, 1 L, 1.5 L, 2 L) as well as beer barrels (50 L or the half-sized 25 L). This unit is most common for all other household size containers of liquids from thermocans to buckets to bath tubs; as well as for fuel
Fuel
Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air...
tanks and consumption for heating or by vehicles.
In countries where the metric system was adopted as the official measuring system after the SI
Si
Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
standard was established, common usage more closely follow contemporary SI
Si
Si, si, or SI may refer to :- Measurement, mathematics and science :* International System of Units , the modern international standard version of the metric system...
conventions. For example, in Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, where the metric system is now in widespread use, consumer beverages are labelled almost exclusively using litres and millilitres. Hectolitres sometimes appear in industry, but centilitres and decilitres are rarely, if ever, used. Larger volumes are usually given in cubic metres (equivalent to 1 kL), or thousands or millions of cubic metres. The situation is similar in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, although kilolitres, megalitres, and gigalitres are commonly used for measuring water consumption, reservoir capacities and river flows.
For larger volumes of fluids, such as annual consumption of tap water, lorry (truck) tanks, or swimming pools, the cubic metre
Cubic metre
The cubic metre is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère...
is the general unit. It is also generally for all volumes of a non-liquid nature.
Fluid flow rates may be measured in litres per unit time interval (second, minute, hour, etc.).
Usages to indicate capacity
Fields where it has become a common measurement for non-liquid volumes, where the capacity of the container is indicated, include:- BerriesBerryThe botanical definition of a berry is a fleshy fruit produced from a single ovary. Grapes are an example. The berry is the most common type of fleshy fruit in which the entire ovary wall ripens into an edible pericarp. They may have one or more carpels with a thin covering and fleshy interiors....
and solid items that can be poured and are measured by their containers - Car boot/trunk size
- Rucksacks & Climbing packs
- Computer caseComputer caseA computer case is the enclosure that contains most of the components of a computer...
s - Microwave ovenMicrowave ovenA microwave oven is a kitchen appliance that heats food by dielectric heating, using microwave radiation to heat polarized molecules within the food...
s - RefrigeratorRefrigeratorA refrigerator is a common household appliance that consists of a thermally insulated compartment and a heat pump that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room...
s - Sleeping bagSleeping bagA sleeping bag is a protective "bag" for a person to sleep in, essentially a blanket that can be closed with a zipper or similar means, and functions as a bed in situations where a bed is unavailable . Its primary purpose is to provide warmth and thermal insulation...
s - packed volume - BinsBinBīn may refer to:* Pungi, a South Asian double clarinet* Veena, a North Indian stick zither* 宾 , a Chinese character meaning guest, visitor...
- Engine displacementEngine displacementEngine displacement is the volume swept by all the pistons inside the cylinders of an internal combustion engine in a single movement from top dead centre to bottom dead centre . It is commonly specified in cubic centimeters , litres , or cubic inches...
See also
- Claude Émile Jean-Baptiste LitreClaude Émile Jean-Baptiste LitreClaude 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....
- Cubic metreCubic metreThe cubic metre is the SI derived unit of volume. It is the volume of a cube with edges one metre in length. An alternative name, which allowed a different usage with metric prefixes, was the stère...
- GallonGallonThe gallon is a measure of volume. Historically it has had many different definitions, but there are three definitions in current use: the imperial gallon which is used in the United Kingdom and semi-officially within Canada, the United States liquid gallon and the lesser used United States dry...
- KilogramKilogramThe kilogram or kilogramme , also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram , which is almost exactly equal to the mass of one liter of water...
- PintPintThe pint is a unit of volume or capacity that was once used across much of Europe with values varying from state to state from less than half a litre to over one litre. Within continental Europe, the pint was replaced with the metric system during the nineteenth century...