Inches to Millimeters
Convert inches (in) to millimeters (mm).
Convert inches to millimeters in one step. One inch equals 25.4 millimeters, so you multiply the number of inches by 25.4. Type in either box to convert both ways — the result updates instantly, entirely in your browser.
| Inches | Millimeters |
|---|---|
| 1 in | 25.4 mm |
| 5 in | 127 mm |
| 10 in | 254 mm |
| 25 in | 635 mm |
| 50 in | 1270 mm |
| 100 in | 2540 mm |
Tip: type in either box to convert both ways, tap a row to reuse it, or use the copy button. Runs entirely in your browser — nothing is uploaded.
Runs entirely in your browser — nothing is uploaded.
How to use the inches to millimeters
- 1Enter the value you want to convert.
- 2Read the converted result instantly — no button to press.
- 3Type in either box to convert both ways, or use the reference table for common values.
Frequently asked questions
How do I convert inches to millimeters?
Multiply the number of inches by 25.4. For example, 1 inches × 25.4 = 25.4 millimeters.
How many millimeters are in a inch?
One inch equals 25.4 millimeters.