What is a Rai?

The rai is the traditional Thai land unit, equal to 1,600 square meters, used in real estate and agriculture.

Overview

The rai equals exactly 1,600 square meters (40 m × 40 m) and is the traditional Thai land unit, still officially used in Thailand for real estate, agriculture, and property records. The rai is divided into 4 ngan (each 400 m²), and 1 ngan equals 100 wa (each 4 m²). Despite Thailand's adoption of the metric system, the rai remains the everyday unit for buying and selling land in Thai contexts — a small urban plot might be 1 rai, while rural farms are quoted in tens or hundreds of rai. The rai relates to the square meter (1 rai = 1,600 m²), the hectare (1 ha = 6.25 rai), and the acre (1 acre ≈ 2.529 rai). The rai's exact metric definition (1,600 m²) makes conversion to SI units precise, unlike many traditional land units.

Symbol

rai

Convert Rai to all units

Live result

rai

Square Meter1,600 m² Square Kilometer0.0016 km² Square Centimeter16,000,000 cm² Square Millimeter1,600,000,000 mm² Hectare0.16 ha Acre0.395369 ac Square Foot17,222.257 ft² Square Inch2,480,005 in² Square Yard1,913.5841 yd² Square Mile0.000618 mi² Dunam1.6 dunam

Relationship to Other Area Units

1 rai equals

Visual reference for how the rai relates to other area units. Each row links to the full converter for that pair.

1 rai=1,600 m² 1 rai=0.0016 km² 1 rai=16,000,000 cm² 1 rai=1,600,000,000 mm² 1 rai=0.16 ha 1 rai=0.395369 ac 1 rai=17,222.257 ft² 1 rai=2,480,005 in² 1 rai=1,913.5841 yd² 1 rai=0.000618 mi² 1 rai=1.6 dunam

When Is the Rai Used?

Thai rural property and farmland
Thai real-estate listings
Agricultural yield reporting in Thailand

Real-world examples

A small Thai farm might be 10–20 rai (1.6–3.2 ha). Thai rice yields: 400–600 kg per rai.

Tips for Using the Rai

1 rai = 1600 m² = 0.16 ha.
1 rai = 4 ngan = 400 tarang wa.
1 hectare = 6.25 rai.

Common Mistakes

Assuming rai equals hectare — only 16%.
Mixing rai with ngan or tarang wa without conversion.
Using rai outside Thailand — not internationally recognised.

Convert Rai to Other Area Units

Rai to Square Meter

1 rai = 1,600 m²

Rai to Square Kilometer

1 rai = 0.0016 km²

Rai to Square Centimeter

1 rai = 16,000,000 cm²

Rai to Square Millimeter

1 rai = 1,600,000,000 mm²

1 rai = 17,222.257 ft²

Rai to Square Inch

1 rai = 2,480,005 in²

Rai to Square Yard

1 rai = 1,913.5841 yd²

Convert Other Units to Rai

Square Meter to Rai

1 m² = 0.000625 rai

Square Kilometer to Rai

1 km² = 625 rai

Square Centimeter to Rai

1 cm² = 6.25 × 10^-8 rai

Square Millimeter to Rai

1 mm² = 6.25 × 10^-10 rai

1 ft² = 0.00005806 rai

1 mi² = 1,618.7426 rai

Dunam to Rai

1 dunam = 0.625 rai

FAQ About the Rai

3 questions

What does the Rai (rai) measure?

The rai measures area. The rai is the traditional Thai land unit, equal to 1,600 square meters, used in real estate and agriculture.

When is the Rai used?

The rai is used in: Thai rural property and farmland; Thai real-estate listings; Agricultural yield reporting in Thailand. A small Thai farm might be 10–20 rai (1.6–3.2 ha). Thai rice yields: 400–600 kg per rai.

How accurate are conversions involving the Rai?

All conversions on Units Converter use NIST SP 811 and BIPM reference values, accurate to 8 significant figures.