A ''rai'' ( th, ไร่, ) is a unit of area equal to 1,600 square metres (16 Hectare#are, ares, 0.16 hectares, 0.3954 acres), and is used in measuring land area for a cadastre or cadastral map.
Its current size is precisely derived from the metre, but is neither part of nor recognized by the modern metric system, the SI, International System (SI).
The rai is defined as 1 square ''sen'' or (40 m × 40 m). It can be divided in four ''ngaan'' or 400 square ''Wa (unit), wa''.
It is commonly used in Thailand. Although recognized by the SI, its use is not encouraged. The word ''rai'' also means plantation.
* Thai units of measurement
* Orders of magnitude (area)
Area metric conversion
British and U.S., Japanese, Chinese, Thai, old French, others.
Units of area
Thai words and phrases