Inch to Millimeter (in to mm)
Convert in to mm — Length converter
One inch equals 25.4 mm, so to convert inches to millimeters you multiply the value by 25.4. A inch is larger than a millimeter — going the other way, 1 mm = 0.03937008 in. For example, 10 in = 254 mm and 50 in = 1270 mm.
25.4Click to copy
1 in = 25.4 mm
Inch to Millimeter formula
1 Inch = 25.4 mm
Worked examples
- 25 in = 635 mm
- 100 in = 2540 mm
Inch to Millimeter conversion table
| Inch (in) | Millimeter (mm) |
|---|---|
| 1 | 25.4 |
| 2 | 50.8 |
| 3 | 76.2 |
| 5 | 127 |
| 8 | 203.2 |
| 10 | 254 |
| 12 | 304.8 |
| 15 | 381 |
| 20 | 508 |
| 25 | 635 |
| 50 | 1270 |
| 100 | 2540 |
| 250 | 6350 |
| 500 | 12700 |
| 1000 | 25400 |
Frequently asked questions
How many millimeters are in one inch?
One inch equals 25.4 millimeters (mm).
How many inches are in one millimeter?
One millimeter equals 0.03937008 inches (in).
How do you convert inches to millimeters?
1 Inch = 25.4 mm. Use the calculator above for any value.
What is 5 in in mm?
5 in = 127 mm.
What is 100 in in mm?
100 in = 2540 mm.
What is 10 in in mm?
10 in = 254 mm.
What is 20 in in mm?
20 in = 508 mm.
Is a inch bigger than a millimeter?
Yes. A inch is larger — one inch equals 25.4 millimeters (mm).