Thai Unit Conversions
Easily convert all Thai area measurement units, such as square wah or tarang wa, ngan, rai, to square meter (m²), square feet (sq ft), acres (ac), or hectares (ha).
Last updated: June 2026
Thai Land Measurement Reference Table
Quick reference for converting between Thai and international area units.
| Unit | m² | sq ft | Acres | Sq Wah | Ngan |
|---|---|---|---|---|---|
| 1 Rai (ไร่) | 1,600 | 17,222 | 0.3954 | 400 | 4 |
| 1 Ngan (งาน) | 400 | 4,306 | 0.0989 | 100 | 1 |
| 1 Square Wah (ตารางวา) | 4 | 43.06 | 0.000988 | 1 | 0.01 |
| 1 Square Meter (m²) | 1 | 10.764 | 0.000247 | 0.25 | 0.0025 |
| 1 Acre | 4,047 | 43,560 | 1 | 1,011.7 | 10.12 |
| 1 Hectare (ha) | 10,000 | 107,639 | 2.471 | 2,500 | 25 |
Understanding Thai Land Measurements
Thailand uses a traditional land measurement system based on the Wah, which dates back centuries. While the metric system is used for most measurements in daily life, property and land transactions in Thailand exclusively use Rai, Ngan, and Square Wah (Tarang Wa). Understanding these units is essential for anyone buying or renting property in Thailand.
Rai (ไร่) — The Largest Unit
One Rai equals 1,600 square meters (about 0.4 acres or 0.16 hectares). Rai is used for larger land plots such as agricultural land, housing developments, and commercial projects. For context, a typical Bangkok condo project might sit on 2–5 Rai of land.
Ngan (งาน) — The Middle Unit
One Ngan equals 400 square meters, or one quarter of a Rai. Ngan is commonly used for medium-sized residential plots, especially for detached houses and townhouses in suburban areas. A typical house plot in a Thai housing estate is around 50–100 Square Wah (half to one Ngan).
Square Wah (ตารางวา) — The Base Unit
One Square Wah (also called Tarang Wa) equals 4 square meters. It is the smallest and most commonly used unit in Thai property listings. Condo land area shares, small house plots, and land prices per unit are all typically quoted in Square Wah. When you see a land price listed as “50,000 per wah,” this refers to the price per Square Wah.
Reading Thai Land Sizes
Thai land sizes are typically expressed using all three units together. For example, “3-2-50” means 3 Rai, 2 Ngan, 50 Square Wah, which equals 3 × 1,600 + 2 × 400 + 50 × 4 = 5,800 square meters. This notation appears on title deeds (Chanote), Land Department records, and property listings throughout Thailand.
Frequently Asked Questions
How many square meters in a Rai?
One Rai (ไร่) equals 1,600 square meters (m²). This is approximately 17,222 square feet, or about 0.4 acres. Rai is the largest common Thai land measurement unit and is used primarily for larger plots of land such as agricultural land, housing estates, and development projects.
What is a Square Wah (Tarang Wa)?
A Square Wah (ตารางวา), also written as Tarang Wa, is the smallest standard Thai land measurement unit. One Square Wah equals 4 square meters (approximately 43 square feet). It is the base unit of the Thai system: 100 Square Wah = 1 Ngan, and 400 Square Wah = 1 Rai. Condo sizes in Thailand are typically measured in Square Wah for the land component.
How do Rai, Ngan, and Square Wah relate to each other?
Thai land measurements follow a simple hierarchy: 1 Rai = 4 Ngan = 400 Square Wah. So 1 Ngan = 100 Square Wah. When Thais describe land size, they often use all three together, for example '2 Rai 1 Ngan 50 Square Wah' which equals 2 × 1,600 + 1 × 400 + 50 × 4 = 3,800 square meters.
How big is one Ngan?
One Ngan (งาน) equals 400 square meters, which is about 4,306 square feet or roughly 0.1 acres. A Ngan is a quarter of a Rai. For perspective, a standard tennis court is about 260 square meters, so one Ngan is about 1.5 tennis courts. Ngan is commonly used for medium-sized residential plots.
Why does Thailand use Rai instead of hectares?
The Rai system predates modern metric standardization in Thailand and remains legally recognized for all land transactions. Thai title deeds (Chanote) and the Land Department use Rai, Ngan, and Square Wah as the official units. While square meters are understood, all property listings, government records, and legal documents in Thailand use the traditional Rai system.
