Hectare (ha)

A hectare (symbol ha) is a unit of area, equal to 10,000 square meters, commonly used for measuring land area. Its base unit, the are, was defined by older forms of the metric system, but is not part of the modern metric system, the International System (SI). 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.