Hectare

From Wikipedia, the free encyclopedia

Comparison of Area units
Unit	SI	SI base
1 ca	1 m²	1 m²
1 a	1 dam²	10² m²
1 ha	1 hm²	10⁴ m²
100 ha	1 km²	10⁶ m²
non-SI comparisons
non-SI	metric	SI base
2.471 acre	1 ha	10⁴ m²
107,639 sq ft	1 ha	10⁴ m²

A hectare (symbol ha) is a unit of area, equal to 10 000 square metres, commonly used for measuring land area. Its base unit, the are, was defined by older forms of the metric system, but neither it nor the hectare are part of the modern metric system. The Comité International des Poids et Mesures classifies the hectare as a unit that, although it is not part of the International System of Units, is expected to continue in use indefinitely, having an exact definition in terms of an SI base unit.

1 Definition
2 Explanation
3 Conversions
4 See also
5 External links

[edit] Definition

1 hectare = 100 ares = 10 000 square metres = 100 metres × 100 metres.

Thus a hectare is the area of a square plot of land where each side of the square is 100 metres, that is, a square hectometre.

The name is a contraction of the SI prefix hecto + are; a hectare is 100 ares.

[edit] Explanation

The hectare is commonly used in many countries, especially in domains concerned with land planning and management such as agriculture, forestry, and town planning where the use of square metres would be cumbersome and unnecessarily precise. In the United States and Canada^{[citation needed]}, the acre is still generally used to describe area measurements in comparable situations.