Area
Popular quickchoices:
hectare (ha) <> square metre (m²)
are (a) <> square metre (m²)
square metre (m²) <> square yard (sq yd)
acre (ac) <> square yard (sq yd)
acre (ac) <> square metre (m²)
acre (ac) <> hectare (ha)
acre (ac) <> are (a)
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*SI (International System of Units):
A modern, coherent system of measurement units, built around seven base units. The SI is officially adopted by almost every country in the world.
*Metric system:
A system of measurement units based on a limited number of fundamental units, introduced by France in 1799. The metric system is the predecessor of the International System of Units (SI).
*US customary system:
The common measurement system of the United States. This system has derived from the imperial system, but has several significant differences.
*Imperial system:
A British measurement system, first standardized in 1824, based on the standard units yard, pound and gallon.