How to convert Inches to Millimeters
To convert inches to millimeters, multiply by 25.4. For example, 5 in × 25.4 = 127 mm.
Inches to Millimeters conversion table
| Inches (in) | Millimeters (mm) |
|---|---|
| 0.25 | 6.35 |
| 0.5 | 12.7 |
| 1 | 25.4 |
| 2 | 50.8 |
| 3 | 76.2 |
| 5 | 127 |
| 10 | 254 |
| 15 | 381 |
| 20 | 508 |
| 25 | 635 |
| 50 | 1270 |
| 75 | 1905 |
| 100 | 2540 |
| 250 | 6350 |
| 500 | 12700 |
| 1000 | 25400 |
About the units
Inches (in) — exactly 2.54 centimeters, used for screen sizes, tools and clothing in the US and UK.
Millimeters (mm) — one thousandth of a meter, the standard unit in engineering drawings and manufacturing.
Frequently asked questions
How many millimeters are in one inche?
One inche equals 25.4 millimeters.
What is the formula to convert inches to millimeters?
Multiply the value in inches by 25.4. For example, 10 in × 25.4 = 254 mm.
How do I convert millimeters back to inches?
Divide by 25.4 — or multiply by 0.039370079. You can also type directly in the second box of the converter above.
Is this converter accurate?
Yes. It uses the internationally defined conversion factors (for example, 1 inch = 2.54 cm exactly and 1 pound = 0.45359237 kg exactly) and shows up to 10 significant digits.
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