Square meter [m2]: the basic unit of area in the SI system. It corresponds to the area of a square with a side of 1 meter.

Square millimeter [mm2]: a unit of area equal to the area of a square with a side of 1 millimeter.

Square centimeter [cm2]: a unit of area equal to the area of a square with a side of 1 centimeter.

Square decimeter [dm2]: a unit of area equal to the area of a square with a side of 1 decimeter.

Square kilometer [km2]: a unit of area equal to the area of a square with a side of 1 kilometer.

Are [a]: a unit of area used in the metric system. It corresponds to the area of a square with a side of 10 meters. 1 are is 100 m2.

Hectare [ha]: a unit of area used in the metric system. It corresponds to the area of a square with a side of 100 meters. 1 hectare is 10,000 m2.

Acre [acre]: a unit of area mainly used in the United States, United Kingdom, and Canada. It corresponds to an area equivalent to 1 morgen, or about 4046.86 m2.

Square inch [in2]: a unit of area mainly used in the United States and United Kingdom. It corresponds to the area of a square with a side of 1 inch (2.54 cm).

Square foot [ft2]: a unit of area mainly used in the United States and United Kingdom. It corresponds to the area of a square with a side of 1 foot (30.48 cm).

Square yard [yd2]: a unit of area mainly used in the United Kingdom and United States. It corresponds to the area of a square with a side of 1 yard (0.9144 meters).