Density is the measure of mass per unit of volume. For any given quantity of material (i.e. air, water, steel), density is calculated by dividing the mass of the material by the volume the material occupies (i.e. ρ = M/V), and is expressed in the units of the mathematical relationship (i.e. kg/m3, lb/ft3 etc.).
For more information on density, see Britannica.com.
Use our free online density unit conversion calculator to easily convert between different units of density including gram/millilitre (g/ml), kilogram/cubic metre (kg/m3), pound/cubic foot (lb/ft3) and pound/cubic inch (lb/in3).