Volume is a measure of how much space an object occupies. Volume is the number of cubic units needed to fill a space.

In the International System of Units (SI), volue is commonly measured in units of cubic metres (m³), cubic centimetres (cm³), cubic millimetres (mm³), cubic kilometres (km³), etc. These units of volume are derived (or compound) units in SI.

Note that although 1 m = 10 dm, 1 m³ = 1000 dm³. [10³ = 1000]

In the Imperial System of Units, volume (in mathematics) is commonly measured in units of cubic inches (in³), cubic feet (ft³), square yards (yd²), cubic miles (mi³), etc.

Note that although 1 ft = 12 in, 1 ft³ = 1728 in³. [12³ = 1728]