SI unit of density is kilograms per cubic metre (kg/m³)

The SI unit of density is kilograms per cubic metre (kg/m³). Density is the mass of a substance per unit of volume. The SI unit of mass is kg, and the SI unit of volume is m³.

Density (ρ) is defined as the mass (m) of an object divided by its volume (V):

​ρ = m/V

Understanding and using the unit of density, kilograms per cubic meter, is fundamental in various scientific and engineering applications, providing a standardised and universally accepted measure for characterizing the compactness of substances.