Hectare

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A hectare (symbol ha) is a unit of area, equal to 10,000 square metres, 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 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.

[edit] Definition

1 hectare = 100 ares = 10,000 square metres = (100 metres)².

Thus a hectare is the area of a square plot of land where each side of the square is 100 metres, that is, a square hectometre.

The name is a contraction of the SI prefix hecto + are; a hectare is 100 ares.

[edit] Explanation

The hectare is commonly used in many countries, especially in domains concerned with land planning and management such as agriculture, forestry, and town planning where the use of square metres would be cumbersome and unnecessarily precise. In the United States and Canada, the acre is still generally used to describe area measurements in comparable situations.

[edit] Conversions

One hectare is equivalent to:

[edit] Metric

• 10 000 square metres = 100 metres × 100 metres (10 000 centiares)
• 100 ares
• 1 square hectometre (a square with sides 100 metres long)
• 10 decares
• 0.01 square kilometre

[edit] English units

• 2.471 053 8 international acres
• 2.471 043 9 U.S. survey acres
• 107,639 square feet
• 0.00386 102 square miles (statute)

[edit] Other

• 15 mus (Chinese)
• 10 dunams (Middle East)
• 10 stremmata (Greece)
• 6.25 rai (Thai)
• 1 cho (Japanese)

[edit] See also

• Orders of magnitude
• conversion of units

• 1 E4 m² for further comparisons

[edit] External links

• Official SI website: Table 6. Non-SI units accepted for use with the International System of Units
• Conversion of hectare in other units