Convert Square Mile to Rai (mi² → rai)

Converting square miles to rais is straightforward: multiply by the conversion factor. Follow these three steps to do it by hand or in your head.

1. 1
   Take your value in square miles

   Start with the number of square miles (mi²) you want to convert.
2. 2
   Multiply by 1,618.7426

   The conversion factor from mi² to rai is 1,618.7426. Multiply your value by this number.
3. 3
   Read the result in rais

   The result is your value in rais (rai).

Multiply the value in square miles by 1,618.7426. For the reverse direction, multiply by 0.000618.

• ✓1 mi² = 2.59 km² = 640 acres.
• ✓US land survey "section" = 1 mi²; "township" = 36 mi².
• ✓Common in US geography; replaced by km² in most of world.

• ✗Confusing square miles with statute miles (length).
• ✗Using 2.5 km² shortcut — correct 2.59 km² differs by 3.5%.
• ✗Mixing nautical square miles (irregular) with statute square miles.

What is the Square Mile?

The square mile equals exactly 2.589988110336 square kilometers (or 640 acres) and is the American unit for measuring large geographic areas: counties, states, watersheds, and large parks. The continental United States covers about 3 million square miles, and Texas alone is 268,597 mi². Population density in US contexts is given in people per square mile (e.g., New York City has about 27,000 people/mi²). The square mile relates to the acre (640 acres = 1 mi²), the square kilometer (1 mi² ≈ 2.59 km²), the square foot (1 mi² = 27,878,400 ft²), and the hectare (1 mi² ≈ 259 ha). It is the natural large-area unit for American geographic discussion, though metric countries use square kilometers for the same purpose.

• US states, counties and cities
• UK geographic and historical boundaries
• Large estate and national-park reporting in Anglo contexts

What is the Rai?

The rai equals exactly 1,600 square meters (40 m × 40 m) and is the traditional Thai land unit, still officially used in Thailand for real estate, agriculture, and property records. The rai is divided into 4 ngan (each 400 m²), and 1 ngan equals 100 wa (each 4 m²). Despite Thailand's adoption of the metric system, the rai remains the everyday unit for buying and selling land in Thai contexts — a small urban plot might be 1 rai, while rural farms are quoted in tens or hundreds of rai. The rai relates to the square meter (1 rai = 1,600 m²), the hectare (1 ha = 6.25 rai), and the acre (1 acre ≈ 2.529 rai). The rai's exact metric definition (1,600 m²) makes conversion to SI units precise, unlike many traditional land units.

• Thai rural property and farmland
• Thai real-estate listings
• Agricultural yield reporting in Thailand