Kilogram per cubic metre is the SI measure of density and is represented as kg/m³, where kg stands for kilogram and m³ stands for cubic metre. The kilogram was originally based on the mass of one litre of water, thus the density of water is about 1000 kg/m³.

kg/m³ is sometimes equivalently written as kg m⁻³.

To convert from g/cm³ to kg/m³, divide by 1,000 for grams to kilograms conversion and multiply by 100³ (there are 100 cm for every 1 metre) for the cm³ to m³ conversion, hence 1 g/cm³ equals 1000 kg/m³.