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 A shape or figure is a graphics, graphical representation of an obje ...

equal to 1,600

square metre The square metre ( international spelling as used by the International Bureau of Weights and Measures) or square meter (American spelling) is the unit of area in the International System of Units (SI) with symbol m2. It is the area of a square w ...

s (16

ares Ares (; grc, Ἄρης, ''Árēs'' ) is the Greek god of war and courage. He is one of the Twelve Olympians, and the son of Zeus and Hera. The Greeks were ambivalent towards him. He embodies the physical valor necessary for success in war b ...

, 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 a ...

s, 0.3954

acre The acre is a unit of land area used in the imperial Imperial is that which relates to an empire, emperor, or imperialism. Imperial or The Imperial may also refer to: Places United States * Imperial, California * Imperial, Missouri * Imp ...

s), and is used in measuring land area for a

cadastre A cadastre or cadaster is a comprehensive recording of the real estate or real property's metes and bounds, metes-and-bounds of a country.Jo Henssen, ''Basic Principles of the Main Cadastral Systems in the World,'/ref> Often it is represented gra ...

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 pref ...

, but is neither part of nor recognized by the modern

metric system The metric system is a system of measurement that succeeded the Decimal, decimalised system based on the metre that had been introduced in French Revolution, France in the 1790s. The historical development of these systems culminated in the d ...

, the International System (SI). The rai is defined as 1 square ''sen'' or (40 m × 40 m). It can be divided in four ''

ngaan A ngan ( th, งาน, , ) is a unit of area, equal to 400 square metres (20 m × 20 m), used for measuring land or property area. Its current size is precisely derived from the metre, but is neither part of nor recognized by the modern metric sy ...

'' 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 bo ...

. 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