what is acre and hectare
From Wikipedia, the free encyclopedia. The hectare (/ËhÉktÉÉr/ or /ËhÉktÉËr/; symbol ha) is an SI accepted metric system unit of area equal to 100 ares (10,000 m2) and primarily used in the measurement of land as a metric replacement for the imperial acre. An acre is about 0.405 hectare and one hectare contains about 2.47 acres. In 1795, when the metric system was introduced, the are was defined as 100 square metres and the hectare (hecto- + are) was thus 100 ares or 1â100 km2. 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.
Most people just know that an acre is a big piece of land, and that 6 acres are more than 5 acres. As a unit of measurement it is hopeless. By contrast, as described in previous comments, 100 m X 100 m = 10 000 square metres (m2) = a hectare (ha), and 100 ha = a square kilometre (km2).