How to convert inches to millimeters
Multiply the number of inches by 25.4:
millimeters = inches × 25.4
Going the other way, 1 millimeter = 0.0393701 inches, so divide millimeters by 25.4 (or multiply by 0.0393701) to get inches.
Example: 25 inches × 25.4 = 635 millimeters.
Inches to millimeters conversion table
| Inches (in) | Millimeters (mm) |
|---|---|
| 1 | 25.4 |
| 2 | 50.8 |
| 3 | 76.2 |
| 5 | 127 |
| 10 | 254 |
| 20 | 508 |
| 25 | 635 |
| 50 | 1,270 |
| 100 | 2,540 |
| 500 | 12,700 |
| 1,000 | 25,400 |
About these units
Inch (in) and millimeter (mm) are both units of length. Metric length units are based on the meter; US customary units (inch, foot, yard, mile) are defined in terms of it — an inch is exactly 25.4 mm.
Related conversions
centimeters to inches · inches to centimeters · millimeters to inches · meters to feet · feet to meters · kilometers to miles · miles to kilometers · yards to meters · meters to yards · all units