The hectare (symbol: ha) is a metric unit used to measure land area. By definition a hectare equals 10,000 square metres — the area of a square with sides 100 metres long. It is a practical unit for describing fields, forests and other plots of land and is widely used in official statistics, cadastral records and land planning. For a concise definition see unit of area or general information about area.
Key characteristics and common conversions
- 1 hectare = 10,000 square metres (10,000 square metres).
- 100 hectares = 1 square kilometre (so 1 hectare = 0.01 km²); see 1 square kilometre for scale.
- 1 hectare = 100 ares; the are is a smaller metric area unit equal to 100 m².
- In non-metric systems, 1 hectare is roughly 2.471 acres (an approximate, widely used conversion).
History and adoption
The hectare was introduced in the years following the French Revolution as part of the reform that produced the metric system. It was intended to provide a convenient unit for land measurement that fits between the square metre and the square kilometre. Although not an SI base unit, the hectare is accepted for use with the International System of Units (SI) and has been adopted by most countries for agricultural and land-record purposes.
Uses and examples
Hectares are commonly reported in agricultural statistics, forestry inventories, land registries and environmental studies. Typical uses include expressing the area of farms, nature reserves, plantation tracts and urban green spaces. Because its scale matches the size of many real-world land parcels, the hectare is convenient for planning and comparison across regions.
Notable distinctions and practical notes
The symbol ha is standard and widely recognized. Though many English-language sources still use acres in particular countries, international reports, scientific publications and most national land administrations use hectares. The related unit are (100 m²) remains in limited use in some places but is much less common than the hectare.