That or the acres or hectares ( Swiss ) is a measure of the surface with the unit symbol ha It is distributed mainly in the agriculture and forestry.


The word is from Greek Hekt hectares ( o) composed ( for a hundred ') and Ar and therefore means: 100 Ar.

1879 acres from the CIPM (Comité International des Poids et Mesures ) was added to its recommendations. Already before the acres was part of the weights and measures of Procedure of the North German Confederation of 1868.

Since the late 19th century corresponded to the German Reich one hectare exactly four acres, this was because of the delineation of traditional dimensions and quarter acre ( vha ) called.


One hectare corresponds to 10,000 square meters or 100 Ar or a square hectometer. A square with the surface area of ​​1 hectare has a side length of 100 meters ( one hectometer ).


Although the square measure not heard acres to the International System of Units ( SI), but it is for use with this admitted. The hectare is in Germany and Austria and as hectares in Switzerland is a legal entity, but restricted to the indication of the area of land and parcels. According to EEC Directive 80/181/EEC is " hectare" is merely a specific name for a hundred times the Ar, formed from the intent Hekto for 100 and the unit name Ar.

Use with SI attachments

The German unit regulation provides Ar ( unit symbol: a) and hectare ( unit symbol: ha ) as independent units and allows for both to the use of SI intentions. Thus, defects such as Hektoar (ha) and, for example Zentihektar ( cha) are legal, but uncommon in Germany. The unit symbol ha is not to be considered whether this hectares or Hektoar is meant, but this makes no difference, since in both cases, 10,000 m² are described.

Other ( non-SI ) units of area in the same size range

  • Ar: 1 a = 0.01 ha
  • Acres: 1 Acre = 0.40468564224 ha
  • Yoke: 33-58 Ar; 3300-5800 m²
  • Morning: 0.1906 to 1.178 ha, mostly between 0.3 and 0.4 ha, later to 0.25 ha
  • Day's work: Calculated by Bavarian Tagwerk ( 3407.27 m²) corresponds to one hectare is about 3 days work.
  • A popular benchmark for the acres is a football field, which usually fails, however small: most common measure of football pitches: 68 meters by 105 meters = 0,714 ha,
  • Minimum according to the Rules: 45 meters by 90 meters = 0,405 ha
  • Maximum according to the Rules: 90 meters by 120 meters = 1,080 ha