What are proper units for density for a solid, liquid or gas

Density of a substance is defined as the mass occupied by the substance per unit volume. Mathematically it can be expressed as:

Density = Mass/Volume

i. e. ρ = m/V

In SI units, the mass is expressed in kilograms (kg) and the volume in cubic meters (m3). Thus,

Density = kg/m3

SI units for density = kg/m3