Rai (Thai) to Square Miles (rai to mi²)

1 rai (Thai) equals 0.0006177634537 square miles (rounded).

1 rai (Thai) = 0.0006177634537 square miles

How to convert rai (Thai) to square miles

To convert rai (Thai) to square miles, multiply the number of rai (Thai) by 0.0006177634537. The factor is rounded to 10 significant digits. To go the other way, multiply square miles by 1,618.742569 (rounded).

square miles = rai (Thai) × 0.0006177634537

Example: 10 rai (Thai) = 0.006177634537 square miles.

About these units

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

Square Mile (mi²)

US & ImperialCurrent unit

640 acres or about 2.59 km². Used for the area of cities, states and countries in the US and UK.

A thousand Roman paces, mille passus, became the mile, and under Elizabeth I Parliament fixed the statute mile at eight furlongs, or 5,280 feet, in place of the older Roman-based value. The square mile inherits that length. Its most famous use came in the United States: the Land Ordinance of 1785 started the Public Land Survey System so that western land could be surveyed and sold to pay war debts, beginning with the Seven Ranges in eastern Ohio.

In that system a section is roughly one square mile, or 640 acres, and a township is 36 sections in a square six miles on a side. One square mile is nearly 2.59 million square meters. Chicago's Midway International Airport, at about 650 acres, covers roughly 1.02 square miles. Beware the phrase mile square: a region 20 miles square has 400 square miles, but so does a rectangle 10 by 40 miles. The US survey version of the mile was retired from 1 January 2023, but the international square mile remains the unit for cities, states and countries in the US and UK.

1 square mile = 2,589,988.11 square meters (approximately).

Sources: Wikipedia: Square mile; Wikipedia: Public Land Survey System; Wikipedia: Mile

Related conversions

See all area units.