Thai land units: rai, ngan and square wah
1 rai = 4 ngan = 400 square wah = 1,600 square metres · 1 ngan = 100 square wah = 400 m² · 1 square wah = 4 m² · and 1 wah = 2 metres, which is a length, not an area (see below).
Thai land unit conversion table
| Unit | Square wah | Square metres |
|---|---|---|
| 1 rai | 400 | 1,600 |
| 1 ngan | 100 | 400 |
| 1 square wah | 1 | 4 |
Land unit converter
Type in any box — the others convert instantly, across rai-ngan-wah, square wah and square metres.
These ratios are fixed by the weights and measures act and do not change year to year. For a real plot, the deed is the authority on its area.
A wah and a square wah are not the same unit
This is the mistake that costs money. A wah is a length of 2 metres; a square wah is an area of 4 m² — that is 2×2 metres. So “how many metres is a square wah” has no direct answer: you cannot equate an area with a length. Confuse the two and a plot is priced 4× wrong.
How to read 1-2-50 on a title deed
The three numbers on a chanote are rai-ngan-wah, not a decimal. 1-2-50 means 1 rai, 2 ngan and 50 square wah — 650 square wah in total, or 2,600 m². It is not 1.250 rai.
Against international units
Then price the plot
Urban land trades in baht per square wah; large upcountry parcels trade per rai. At ฿35,000 per square wah, the 1-2-50 plot above comes to 650 × 35,000 = ฿22,750,000. From there the transfer-fee calculator works out what the Land Department will charge.
Thai land unit FAQ
How many square wah in 1 rai?
1 rai is 400 square wah, which is 4 ngan or 1,600 square metres.
How many square wah in 1 ngan?
1 ngan is 100 square wah, or 400 square metres. 4 ngan make 1 rai.
How many square metres is 1 rai?
1 rai is 1,600 square metres, because a rai is 400 square wah and each square wah is 4 m².
What is a square wah in square metres?
1 square wah is 4 m² — an area 2 metres on each side.
Is a wah the same as a square wah?
No. A wah is a length of 2 metres; a square wah is an area of 4 m². Treating them as the same makes a plot 4 times the wrong size.
How big is 1 rai?
1 rai is 1,600 square metres — a square 40 metres on each side.
How many rai in a hectare?
1 hectare is 6.25 rai, and 1 rai is 0.16 hectares or about 0.3954 acres.
What does 1-2-50 mean on a title deed?
It means 1 rai, 2 ngan and 50 square wah — 650 square wah in total. It is not a decimal.
Looking for land?
Browse land for sale across Thailand on Jaotin