How is land measured in Thailand?

When buying property in Thailand, you'll encounter a few terms relating to land measurements that you might not be familiar with: square wah, ngan, and rai:

• 1 square wah = 4 sq. meters
• 1 ngan = 100 sq. wah = 400 sq. m
• 1 rai = 4 ngan = 1600 sq. m

And some common reverse conversions as well:

• 1 hectare = 6.25 rai = 10,000 sq. m
• 1 acre = 2.47 rai = 43,560 sq. ft