Traditional units of measurement in Thailand
Southeast Asia · 6 documented units · reviewed 2026-07-31
Quick answer
Thai land is legally measured in rai, ngan and square wah: 1 rai = 1,600 m², 1 ngan = 400 m², 1 square wah = 4 m². These are exact by statute.
How measurement works in Thailand
Thailand is one of the few countries where the traditional land system is still the statutory one. Title deeds (chanote) state area in rai, ngan and square wah, and because the wah was metricated to exactly 2 metres, every step of the system is an exact metric quantity.
Gold trades in baht weight, fixed at 15.244 g for jewellery-grade gold, and Thai gold shops quote prices per baht rather than per gram.
Tical is the older Western transliteration of the same baht weight and shows up in colonial-era and numismatic sources.
area units of Thailand
| Unit | Value in SI | Typical use | Convert |
|---|---|---|---|
| Rai (ไร่) | 1 Rai (ไร่) = 1,600 square metre | agriculture | Rai (ไร่) → square metresIn-depth guide |
| Ngan (งาน) | 1 Ngan (งาน) = 400 square metre | agriculture | Ngan (งาน) → square metresIn-depth guide |
| Talang Wah (ตร.วา) | 1 Talang Wah (ตร.วา) = 4 square metre | surveying | Talang Wah (ตร.วา) → square metresIn-depth guide |
mass units of Thailand
| Unit | Value in SI | Typical use | Convert |
|---|---|---|---|
| Baht (weight) | 1 Baht (weight) = 0.01518 kilogram | jewellery, precious-metals | Baht (weight) → kilogramsIn-depth guide |
| Tical/Kyat | 1 Tical/Kyat = 0.01633 kilogram | jewellery, precious-metals | Tical/Kyat → kilogramsIn-depth guide |
| Pikul/Pecul | 1 Pikul/Pecul = 60.479 kilogram | trade, agriculture | Pikul/Pecul → kilogramsIn-depth guide |
Before you convert
- Square wah, not wah, is the area unit — a linear wah is 2 m, a square wah is 4 m².
- Baht as a currency and baht as a mass unit share a name; gold quotes always mean the mass.
Sources
- Thai Ministerial Regulation on Weights and Measures (metrication of the wah)
See our methodology and data provenance pages, or review published corrections.