Rai, ngan and square wa

How to use it

1. Type the area from the title deed in rai, ngan and square wa; leave a box empty if it has none. Square meters, square wa, hectares, acres and square feet show at once.
2. Type a price per square wa to get the price of the whole plot.
3. If you have square meters, or the width and length of a rectangular plot, use the cards below to get rai, ngan and square wa.

How it is worked out

1 rai = 4 ngan = 400 square wa = 1,600 m², 1 ngan = 100 square wa = 400 m², 1 square wa = 4 m² (a wa is 2 meters). Square meters = rai × 1,600 + ngan × 400 + square wa × 4, so 2 rai 3 ngan 50 square wa = 3,200 + 1,200 + 200 = 4,600 m².

Back again: square wa = m² ÷ 4 (rounded to 2 decimals); every 400 square wa make a rai, every 100 left make a ngan, and the rest stays square wa. So 5,000 m² = 1,250 square wa = 3 rai 0 ngan 50 square wa. 1 hectare = 10,000 m² = 6.25 rai, 1 acre = 4,046.8564224 m². Price = square wa × price per square wa, rounded to the satang.

Good to know

• Decimals, thousands separators and Thai digits are fine. Values over the usual range, such as 5 ngan, work too, and the line "as rai, ngan, wa" sorts them out.
• Width × length only fits a rectangular plot. For other shapes, use the area on the deed or ask a surveyor.
• This is arithmetic only: official appraisal prices and transfer fees come from the Treasury Department and the Department of Lands.
• More area units, and Thai lengths such as wa, sok and sen, are in the unit converter.

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