Convert Rai to Acre (rai → ac)

Converting rais to acres 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 rais

   Start with the number of rais (rai) you want to convert.
2. 2
   Multiply by 0.395369

   The conversion factor from rai to ac is 0.395369. Multiply your value by this number.
3. 3
   Read the result in acres

   The result is your value in acres (ac).

Multiply the value in rais by 0.395369. For the reverse direction, multiply by 2.529285.

• ✓1 rai = 1600 m² = 0.16 ha.
• ✓1 rai = 4 ngan = 400 tarang wa.
• ✓1 hectare = 6.25 rai.

• ✗Assuming rai equals hectare — only 16%.
• ✗Mixing rai with ngan or tarang wa without conversion.
• ✗Using rai outside Thailand — not internationally recognised.

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

What is the Acre?

The acre equals exactly 4,046.8564224 square meters (or 43,560 square feet) and is the standard unit for American and British farmland, real estate, and recreational property. The unit's origin is medieval: an acre was the area a yoke of oxen could plow in one day, traditionally a strip 1 furlong (660 ft) by 1 chain (66 ft). Despite metric adoption in many fields, the acre persists in property records throughout the US and UK. A standard American football field (excluding end zones) is about 1.32 acres. The largest US state, Alaska, contains about 365 million acres. The acre relates to the square foot (43,560 ft² = 1 acre), the hectare (1 ha ≈ 2.471 acres), the square mile (640 acres = 1 mi²), and the square meter (1 acre ≈ 4,047 m²). US farms average around 446 acres, and the average UK farm is about 215 acres.

• US farmland and ranches
• UK rural property and estates
• Canadian rural property (legal survey system)