A
gram per litre or
gram per liter (
g/L or
g/l) is a unit of measurement of
mass concentration that shows how many
grams of a certain
substance are present in one
litre of a usually liquid or gaseous mixture. It is not an
SI unit because it contains the non-SI unit
litre. The SI unit of mass concentration is
kilogram per cubic metre, which is equivalent (1 g/L = 1 kg/m
3).