Density is the mass per unit volume of a substance. The formula for density is:
density = mass/volume.
The unit for mass is kilograms (kg)/grams (g) and volume in centimetres cubed (cm3) or metres cubed (m3).
Example 1. A stone of mass 20 kg with volume 4 cm3 calculate its density.
density = mass/volume = 20kg/4cm3 = 5kg/cm3