Convert Inches to Millimeters
Convert Inches (in) to Millimeters (mm) instantly. Enter a value below and the result updates live — accurate to 8 significant figures. 1 Inches = 25.4 Millimeters.
Numbers round to 8 significant figures — the underlying math is full-precision.
Inches to Millimeters formula
Multiply the Inches value by 25.4.
mm = in × 25.400000000000002
Inches to Millimeters conversion table
| Inches (in) | Millimeters (mm) |
|---|---|
| 1 | 25.4 |
| 5 | 127 |
| 10 | 254 |
| 20 | 508 |
| 50 | 1270 |
| 100 | 2540 |
| 500 | 12700 |
| 1000 | 25400 |
Inches to Millimeters — FAQ
What is 1 in in mm?
1 Inches (in) equals 25.4 Millimeters (mm). For example, 10 in = 254 mm.
How do I convert Inches to Millimeters?
Multiply the Inches value by 25.4. Or simply type any value into the converter above and the Millimeters result updates instantly.
Is the Inches to Millimeters conversion accurate?
Yes. The conversion uses the exact internationally-defined factor: 1 in = 25.400000000000002 mm. Results are shown to 8 significant figures.
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