In chemistry, the molar volume of a substance is the volume of one mole of that substance. It can be computed as the substance's atomic or molecular weight, divided by its density. The SI unit for volume is m3.

Thus, the SI unit of molar volume is cubic meters per mole (m3mol-1).

Cubic centimetres (cm3) a measure of volume one million times smaller than a cubic meter, are sometimes also used, to give units of cm3mol-1.

The molar volume is usually given for a solid substance at 298 K. Apart from temperature and density, it depends on phase and allotrope of the substance.