Convert Square Millimeters to Rai
Convert Square Millimeters (mm²) to Rai (rai) instantly and accurately.
Conversion Formula
rai = mm² × 6.250000000e-10
About Square Millimeters
A square millimeter (mm²) is a metric unit of area equal to a square with sides of one millimeter. It is commonly used in precision engineering, electronics, and measuring very small surfaces such as microchips or printed circuit boards. To visualise: a typical pinhead has an area of about 2-3 mm². This unit is essential in microscopy, medical imaging, and manufacturing where tiny, precise measurements are critical.
About Rai
A rai (ไร่) is the standard Thai unit of land area, defined as exactly 1,600 m² (40 m × 40 m). It is used throughout Thailand for all land measurement - from rice paddies to urban plots and national parks. Thai real estate listings always quote land area in rai, ngan (400 m² = ¼ rai), and talang wah (4 m² = 1 square wah). Thailand's total rice-paddy area is reported in millions of rai. One rai equals approximately 0.395 acres or 0.16 hectares.
Quick Reference Table
| Square Millimeters (mm²) | Rai (rai) |
|---|---|
| 1 mm² | 6.25 × 10-10 rai |
| 2 mm² | 1.25 × 10-9 rai |
| 5 mm² | 3.125 × 10-9 rai |
| 10 mm² | 6.25 × 10-9 rai |
| 25 mm² | 1.563 × 10-8 rai |
| 50 mm² | 3.125 × 10-8 rai |
| 100 mm² | 6.25 × 10-8 rai |