Hectare
| hectare | |
|---|---|
A visualisation of one hectare | |
| General information | |
| Unit system | Non-SI units mentioned in the SI |
| Unit of | Area |
| Symbol | ha |
| Conversions | |
| 1 ha in ... | ... is equal to ... |
| SI base units: | 104 m2 |
| Imperial and US customary units | 11960 yd2 2.4711 acres |
The hectare (/ˈhɛktɛər, -tɑːr/; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), that is, 10,000 square metres (10,000 m2), and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is about 0.405 hectares and thus one hectare is about 2.47 acres.
In 1795, when the metric system was introduced, the are was defined as 100 square metres, or one square decametre, and the hectare ("hecto-" + "are") was thus 100 ares or 1/100 km2 (10000 square metres). When the metric system was further rationalised in 1960, resulting in the International System of Units (SI), the are was not included as a recognised unit, and from 2026 the hectare is no longer described by the International Bureau of Weights and Measures (BIPM) as accepted for use with the SI.