Inch to Millimeter Converter
1 Inch = 25.4 Millimeters. To convert Inches to Millimeters, multiply by 25.4.
Result updates as you type
Recent:
1 Inch = 25.4 Millimeter
Formula
To convert Inches to Millimeters, multiply the value by 25.4. One Inch equals 25.4 Millimeters.
mm = in × 25.4
For a quick mental estimate, multiply Inches by about 25 — the exact factor is 25.4.
Worked examples
- 1 Inch = 25.4 Millimeters
- 5 Inches = 127 Millimeters
- 10 Inches = 254 Millimeters
- 100 Inches = 2540 Millimeters
Inches to Millimeters table
| Inches (in) | Millimeters (mm) |
|---|---|
| 1 | 25.4 |
| 2 | 50.8 |
| 3 | 76.2 |
| 4 | 101.6 |
| 5 | 127 |
| 10 | 254 |
| 25 | 635 |
| 50 | 1270 |
| 100 | 2540 |
| 250 | 6350 |
| 500 | 12700 |
| 1000 | 25400 |
About Inch and Millimeter
Both the Inch (in) and the Millimeter (mm) measure length. One Inch is equal to 25.4 Millimeters, so you can convert any measurement by multiplying by 25.4. The calculator above updates instantly, and the reference table lists common Inch-to-Millimeter values for quick lookups.
Unit definitions
- Inch (in)
- The Inch (in) is a unit of length equal to 0.0254 Meters.
- Millimeter (mm)
- The Millimeter (mm) is a unit of length equal to 0.001 Meters.
Frequently asked questions
- How do you convert Inches to Millimeters?
- Multiply the number of Inches by 25.4. For example, 1 Inch × 25.4 = 25.4 Millimeters.
- How many Millimeters are in a Inch?
- There are 25.4 Millimeters in one Inch.
- What is 10 Inches in Millimeters?
- 10 Inches is equal to 254 Millimeters.
- How do you convert Millimeters back to Inches?
- Multiply the number of Millimeters by 0.03937008 to get Inches. One Millimeter equals 0.03937008 Inches.