Units[edit]

A square metre quadrat made of PVC pipe.

Every unit of length has a corresponding unit of area, namely the area of a square with the given side length. Thus areas can be measured in square metres (m^{2}), square centimetres (cm^{2}), square millimetres (mm^{2}), square kilometres (km^{2}), square feet (ft^{2}), square yards (yd^{2}), square miles (mi^{2}), and so forth.^{[11]} Algebraically, these units can be thought of as the squares of the corresponding length units.

The SI unit of area is the square metre, which is considered an SI derived unit.^{[3]}