Hectare vs. Hectacre — What's the Difference?

The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), or 10,000 m2, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre.

(rare) One hundred acres.

A metric unit of area equal to 100 ares (2.471 acres). See Table at measurement.

Hectare.

A unit of surface area (symbol ha) equal to 100 ares (that is, 10,000 square metres, one hundredth of a square kilometre, or approximately 2.5 acres), used for measuring the areas of geographical features such as land and bodies of water.

A measure of area, or superficies, containing a hundred ares, or 10,000 square meters, and equivalent to 2.471 acres.

(abbreviated `ha') a unit of surface area equal to 100 ares (or 10,000 square meters)