Litre

The litre (spelled litre in Commonwealth English [1] and liter in American English) is a unit of volume.

Symbols

There are two official symbols, the Latin letter el in both cases: l and L. The litre is not an SI unit but is accepted for use with the SI. The SI unit of volume is the cubic metre (m³).

Definitions and equivalents

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

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

SI prefixes applied to the litre

The litre may be used with some SI prefixes.

Multiple	Name	Symbols			Multiple	Name	Symbols
100	litre	l	L
101	decalitre	dal	daL		10−1	decilitre	dl	dL
102	hectolitre	hl	hL		10−2	centilitre	cl	cL
103	kilolitre	kl	kL		10−3	millilitre	ml	mL
106	megalitre	Ml	ML		10−6	microlitre	µl	µL
109	gigalitre	Gl	GL		10−9	nanolitre	nl	nL
1012	teralitre	Tl	TL		10−12	picolitre	pl	pL
1015	petalitre	Pl	PL		10−15	femtolitre	fl	fL
1018	exalitre	El	EL		10−18	attolitre	al	aL

Other common metric equivalencies

• 1 µL (microlitre) = 1 mm³ (cubic millimetre)
• 1 mL (millilitre) = 1 cm³ (cubic centimetre)

Conversions

One litre

≈ 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

Explanation

Litres are most commonly used for items measured by the capacity or size of their container (such as fluids and berries), 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. Similarly: 1 mL of water has about 1 g of mass; 1000 litres of water has about 1000 kg (1 tonne) of mass. This relationship is due to the history of the unit, but since 1964 it has not been part of the definition.

Symbol

Originally, the only symbol for the litre 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.

See also [2]

History

See [3]

See also

• Pint
• Gallon
• Kilogram
• Cubic metre

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