A Litre is a measure of capacity (Volume). 1 litre is 1000
cubic centimeters, about 1¾ pints. Litre is abbreviated
to l. 1 gallon is about 4.55 litres.
petrol tank of a typical small car holds about 40 litres.
A bath uses about 90 litres; a shower is more economical,
using only about 30 litres. Litres are most commonly used
for items (such as fluids 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 degrees celsius. Similarly, 1 millilitre of water has about
1 g of mass; 1,000 litres of water has about 1,000 kg of mass.
This relationship is because the gram was originally defined
as the mass of 1 ml of water.