A ''rai'' ( th, ไร่, ) is a unit of

area Area is the quantity that expresses the extent of a region on the plane or on a curved surface. The area of a plane region or ''plane area'' refers to the area of a shape or planar lamina, while '' surface area'' refers to the area of an ope ...

equal to 1,600 square metres (16 ares, 0.16

hectare The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100- metre sides (1 hm2), or 10,000 m2, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is ...

s, 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 The metre (British spelling) or meter (American spelling; see spelling differences) (from the French unit , from the Greek noun , "measure"), symbol m, is the primary unit of length in the International System of Units (SI), though its prefi ...

, but is neither part of nor recognized by the modern

metric system The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...

, the 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''. It is commonly used in

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...

. Although recognized by the SI, its use is not encouraged. The word ''rai'' also means

plantation A plantation is an agricultural estate, generally centered on a plantation house, meant for farming that specializes in cash crops, usually mainly planted with a single crop, with perhaps ancillary areas for vegetables for eating and so on. The ...

References

External links

Area metric conversion
British and U.S., Japanese, Chinese, Thai, old French, others. {{DISPLAYTITLE:''Rai'' (unit) Units of area Thai units of measurement

See also

References

External links