The hectare (/ˈhɛktɛər/ or /ˈhɛktɑːr/), although not a unit of SI, is the only named unit of area that is accepted for use within the SI. In practice the hectare is fully derived from the SI, being equivalent to a square hectometre. It is widely used throughout the world for the measurement of large areas of land, and it is the legal unit of measure in domains concerned with land ownership, planning, and management, including law (land deeds), agriculture, forestry, and town planning throughout the European Union. The United Kingdom, United States, Burma, and to some extent Canada instead use the acre.
| Definition | Relation to SI units |
|---|---|
≡ 10000 m2 |
| millibarn | board | section | attobarn | hide | zeptobarn | square chain (international) | barn |
|---|---|---|---|---|---|---|---|
| 1 | 1.2916692500052 × 10-29 | 3.8610215854245 × 10-38 | 1.0 × 1015 | 2.0 × 10-37 | 1.0 × 1018 | 2.4710538146717 × 10-34 | 0.001 |
| 7.74192 × 1028 | 1 | 2.9891720232629 × 10-9 | 7.74192 × 1043 | 1.548384 × 10-8 | 7.74192 × 1046 | 1.9130700948883 × 10-5 | 7.74192 × 1025 |
| 2.589988110336 × 1037 | 334 540 800 | 1 | 2.589988110336 × 1052 | 5.1799762 | 2.589988110336 × 1055 | 6 400 | 2.589988110336 × 1034 |
| 1.0 × 10-15 | 1.2916692500052 × 10-44 | 3.8610215854245 × 10-53 | 1 | 2.0 × 10-52 | 1 000 | 2.4710538146717 × 10-49 | 1.0 × 10-18 |
| 5.0 × 1036 | 64,583,462.500258 | 0.1930511 | 5.0 × 1051 | 1 | 5.0 × 1054 | 1,235.5269073 | 5.0 × 1033 |
| 1.0 × 10-18 | 1.2916692500052 × 10-47 | 3.8610215854245 × 10-56 | 0.001 | 2.0 × 10-55 | 1 | 2.4710538146717 × 10-52 | 1.0 × 10-21 |
| 4.0468564224 × 1033 | 52 272 | 0.0001563 | 4.0468564224 × 1048 | 0.0008094 | 4.0468564224 × 1051 | 1 | 4.0468564224 × 1030 |
| 1 000 | 1.2916692500052 × 10-26 | 3.8610215854245 × 10-35 | 1.0 × 1018 | 2.0 × 10-34 | 1.0 × 1021 | 2.4710538146717 × 10-31 | 1 |
| Symbol | Definition |
|---|---|
| ≡ | exactly equal |
| ≈ | approximately equal to |
| = | equal to |
| digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |
| 1 hectares | = 10000 square meters |
| 2 hectares | = 20000 square meters |
| 3 hectares | = 30000 square meters |
| 4 hectares | = 40000 square meters |
| 5 hectares | = 50000 square meters |