Standard area units
These are exact by definition (1 ft = 0.3048 m). The Land Measure app shows all seven of them.
| Unit | Square meters | Square feet | Acres |
|---|---|---|---|
| 1 square meter | 1 | 10.76391 | 0.00024711 |
| 1 square foot | 0.09290304 | 1 | 0.00002296 |
| 1 square yard | 0.83612736 | 9 | 0.00020661 |
| 1 acre | 4,046.8564224 | 43,560 | 1 |
| 1 hectare | 10,000 | 107,639.104167 | 2.47105381 |
| 1 square kilometer | 1,000,000 | 10,763,910.41671 | 247.10538147 |
| 1 square mile | 2,589,988.110336 | 27,878,400 | 640 |
How to convert
Every conversion goes through square meters: multiply by the “from” unit’s size in m², then divide by the “to” unit’s size in m².
A common mistake is converting lengths with a linear factor and forgetting to square it: a foot is 0.3048 m, but a square foot is 0.3048² = 0.09290304 m², not 0.3048 m².
Traditional and regional units
Units such as the bigha, katha, marla, kanal, guntha and cent in South Asia, the rai in Thailand, the tsubo and pyeong in Japan and Korea, the mu in China and the feddan and dunam in the Middle East are still used to buy and sell land. Some are fixed by law; others vary from one state or district to the next. Each has its own page with its regional values, sources and conversions:
- Bigha
- Biswa
- Katha
- Lessa
- Dhur
- Kanal
- Marla
- Killa
- Murabba
- Guntha
- Cent
- Decimal
- Ground
- Kani
- Ropani
- Aana
- Acre
- Rai
- Ngan
- Square wah
- Tsubo
- Pyeong
- Ping
- Jia
- Mu
- Feddan
- Dunam
- Jerib
- Morgen
- Are
- Hectare
- Arpent
- Manzana
- Cuerda
- Labor
- Rood
- Perch
- Section
- Township
See the land units hub for the full list by region, or popular conversions like acres to hectares and square feet to acres.