Litres are most commonly used for items (such as fluids and solids that can be poured) 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.
A litre is the volume of a cube with sides of 10 cm, which is slightly less than a cube of sides 4 inches (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 4.88% higher than the 27-litre approximation.
In spoken English, the symbol "mL" (for millilitre) can be pronounced as "mil". This can potentially cause confusion with some other measurement words such as: