Square kilometre (km²)
The square kilometre (symbol: km²) is an SI derived unit of area equal to one million square metres (10⁶ m²), representing the area of a square with sides of one kilometre. Formally defined through the SI base unit of length (the metre), it is the global standard for measuring large geographical areas, such as municipal boundaries, national territories, body-of-water surface areas, and planetary landmasses.
Metric
- Square kilometre (km²)1
- Hectare (ha)100
- Are (a)10,000
- Square metre (m²)1,000,000
- Square decimetre (dm²)100,000,000
- Square centimetre (cm²)1×10¹⁰
- Square millimetre (mm²)1×10¹²
- Square micrometre (µm²)1×10¹⁸
- Square nanometre (nm²)1×10²⁴
British/American
- Township0.01
- Square mile0.39
- Homestead1.54
- Acre247.11
- Rood988.42
- Square rod39,536.87
- Square107,639.1
- Square yard (yr²)1,195,990
- Square foot (ft²)10,763,910
- Square inch (in²)1.55×10⁹
Other
- Metric dunam1,000
- Cypriot dunam747.49
- Iraqi dunam400
- Football pitch140.06
Brazilian
- Alqueire paulista41.32
- Alqueire mineiro20.66
- Alqueire baiano10.32
- Alqueire do norte36.76