Square Meters to Rai (Thai) (m² to rai)

1 square meter equals 0.000625 rai (Thai) exactly.

1 square meter = 0.000625 rai (Thai)

How to convert square meters to rai (Thai)

To convert square meters to rai (Thai), multiply the number of square meters by 0.000625. This factor is exact. To go the other way, multiply rai (Thai) by 1,600.

rai (Thai) = square meters × 0.000625

Example: 10 square meters = 0.00625 rai (Thai).

About these units

Square Meter (m²)

Metric (SI)Current unit

The SI unit of area: a square one meter on each side. Used for floor areas and property sizes in most of the world.

Squaring the meter was built into the metric system from the start. The French law of 18 Germinal, Year III (7 April 1795) defined the are, the land unit that gave the hectare its name, as exactly 100 square meters, so the square meter was already the foundation of metric land measure. Nobody is credited with inventing it as a separate unit. It is simply the area of a square one meter on each side, and any SI prefix that works for the meter works for it, with the prefix squared along with the unit.

That squaring catches people out: a square kilometer is one million square meters, not one thousand. Since 1983 the meter has been defined through the speed of light, so the square meter is tied to a constant of nature as well as to the second. A hectare, about the area of Trafalgar Square in London, is 10,000 square meters. In everyday terms one square meter is about 10.76 square feet. Unicode has a compatibility character for it, but the recommended way to write it is the plain superscript two: m².

The square meter is the reference unit for area on this site.

Sources: Wikipedia: Square metre; Wikipedia: Are (unit); NIST: the meter and the SI redefinition

Rai (Thai) (rai)

ThaiTraditional unit (still used in some regions)

Exactly 1,600 m² (about 0.4 acre). The standard unit of land in Thailand.

Rai is a Thai word for a field or plantation, and it is the standard unit for farmland and rural property in Thailand. One rai is the area of a square one sen on each side, which with a sen of 40 m gives 1,600 square meters, or 16 ares.

That is roughly 0.4 acre, so a hectare holds 6.25 rai. The rai is divided into 4 ngan and 400 square wa, and official land documents record areas in these three tiers, sometimes in shorthand such as 4-2-25 for 4 rai, 2 ngan and 25 square wa.

Older land measures in the region were looser, but the cadastral survey started in 1896 fixed the units against metric lengths. The rai is therefore exact today, and it is still the unit in which Thai land is bought, sold and taxed.

1 rai (Thai) = 1,600 square meters (exactly).

Sources: Wikipedia: Rai (unit); Wikipedia: Thai units of measurement

Related conversions

See all area units.