Inches to Millimeters
Convert Inches to Millimeters with an exact factor. One inch equals 25.4 Millimeters.
Result25.4
How to convert Inches to Millimeters
The converter above changes Inches into Millimeters instantly. As a reference point, one inch corresponds to 25.4 Millimeters, and one millimeter corresponds to 0.03937008 Inches. Use the table below for common values.
Inches × 25.4 = Millimeters
For example, 5 Inches = 127 Millimeters.
About the units
- Inches (in) — Exactly 2.54 cm, used in the US, UK and for screens.
- Millimeters (mm) — One thousandth of a metre.
Inches to Millimeters conversion table
| Inches | Millimeters |
|---|---|
| 1 in | 25.4 mm |
| 2 in | 50.8 mm |
| 3 in | 76.2 mm |
| 4 in | 101.6 mm |
| 5 in | 127 mm |
| 10 in | 254 mm |
| 15 in | 381 mm |
| 20 in | 508 mm |
| 25 in | 635 mm |
| 50 in | 1,270 mm |
| 100 in | 2,540 mm |
| 500 in | 12,700 mm |
| 1,000 in | 25,400 mm |
Millimeters to Inches conversion table
| Millimeters | Inches |
|---|---|
| 1 mm | 0.03937008 in |
| 2 mm | 0.07874016 in |
| 3 mm | 0.11811024 in |
| 4 mm | 0.15748031 in |
| 5 mm | 0.19685039 in |
| 10 mm | 0.39370079 in |
| 15 mm | 0.59055118 in |
| 20 mm | 0.78740157 in |
| 25 mm | 0.98425197 in |
| 50 mm | 1.96850394 in |
| 100 mm | 3.93700787 in |
| 500 mm | 19.68503937 in |
| 1,000 mm | 39.37007874 in |
Frequently asked questions
How many Millimeters is one inch?
One inch is 25.4 Millimeters.
Are these length conversions accurate?
Yes. They use the exact standard unit definitions, so results are accurate to the number of decimals shown.
What is the formula to convert Inches to Millimeters?
Multiply the number of Inches by 25.4. To convert back, multiply Millimeters by 0.03937008.
This tool is provided for general information only. Verify important figures independently. · Last reviewed: August 25, 2026