Land in Thailand is measured in Rai, Ngan and Wah.

1 Rai = 4 Ngan (or 1600 Sq.m.)
1 Ngan = 100 Wah (or 400 Sq.m.)
1 Wah = 4 Sq.m.
1 Acre = 2.5 Rai (approx.)
1 Hectare = 6.25 Rai (approx.)

Metric measures are usually used in the construction and measurement of buildings
Land prices are usually expressed in Baht per Rai or (for smaller plots) Baht per Wah
We use the Thai Baht and Euro on our website.