Thailand traditionally uses different measurement units for land areas. However, they are easily convertible to square meters (sqm) or square feet (SF).
The three Thai land area measurements are Wah, Ngan and Rai:
Wah (1 Wah = 4 sqm = 43 SF)
Ngan (1 Ngan = 100 Wah = 0.25 Rai = 400 sqm = 4,305 SF = 0.1 Acre = 0.04 Hectare)
Rai (1 Rai = 400 Wah = 4 Ngan = 1600 sqm = 17,222 SF = 0.40 Acre = 0.16 Hectare)
Living areas may sometimes also be measured in Wah, but most commonly square meters (sqm) are being used.
Below is a table with more conversion details: