Convert Square Kilometer to Rai (km² → rai)

Converting square kilometers 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 kilometers

   Start with the number of square kilometers (km²) you want to convert.
2. 2
   Multiply by 625

   The conversion factor from km² to rai is 625. 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 kilometers by 625. For the reverse direction, multiply by 0.0016.

• ✓1 km² = 100 hectares = 1,000,000 m².
• ✓1 km² = 0.386 square miles.
• ✓Multiply km × km in metric to get km² — but always keep consistent units.

• ✗Mixing km² and km when comparing geography — 10 km is a length, 10 km² is an area.
• ✗Confusing km² with the square mile (mi²) in international comparisons.
• ✗Reading "million km²" as "km²" on continental-scale maps — factor of 10⁶.

What is the Square Kilometer?

The square kilometer equals 1,000,000 square meters (or 100 hectares) and is the international standard for measuring large areas: cities, national parks, lakes, watersheds, and country-level statistics. Population density is conventionally given in people per km² (e.g., Singapore has roughly 8,400 people/km², Mongolia has fewer than 2). The largest US national park, Wrangell-St. Elias in Alaska, covers about 53,000 km². France is 643,801 km², and the largest country, Russia, spans 17 million km². The square kilometer relates to the square meter (1 km² = 1,000,000 m²), the hectare (1 km² = 100 ha), the square mile (1 km² ≈ 0.386 mi²), and the acre (1 km² ≈ 247.1 acres). Geographic information systems, climate science, and regional planning all rely on square kilometers as the base unit for area.

• Country and city geographic area reporting
• National-park and protected-area sizes
• Large-scale environmental studies (deforestation, etc.)

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