Convert inches to mm
1 inch equals 25.4 millimeters. To convert inches to millimeters, multiply the number of inches by 25.4: for example, 10 in is 254 mm. Ethical Tube's free inches to mm converter does the math as you type, and the chart below lists common values.
1 in = 25.4 mm
- 1 in
- 25.4 mm
- 1 mm
- 0.0393701 in
- Formula
- mm = in × 25.4
- Measures
- Length
- Price
- Free
- Works offline
- Yes
Conversion chart
inches to mm chart
| Inches (in) | Millimeters (mm) |
|---|---|
| 1 in | 25.4 mm |
| 2 in | 50.8 mm |
| 3 in | 76.2 mm |
| 4 in | 101.6 mm |
| 5 in | 127 mm |
| 6 in | 152.4 mm |
| 8 in | 203.2 mm |
| 10 in | 254 mm |
| 12 in | 304.8 mm |
| 15 in | 381 mm |
| 20 in | 508 mm |
| 25 in | 635 mm |
| 50 in | 1,270 mm |
| 100 in | 2,540 mm |
How it works
How to convert inches to mm
Know the formula
mm = in × 25.4. In words: multiply the number of inches by 25.4.
Work an example
10 in → 254 mm. Round to two or three decimal places for everyday use.
Or type it in
Enter any value in the converter above and the answer appears instantly, in both directions.
Good to know
About length units
- Since 1959, one inch is defined as exactly 2.54 centimeters, so conversions between metric and US lengths are exact.
- A foot is 12 inches, a yard is 3 feet, and a mile is 5,280 feet.
FAQ
Questions, answered
How many millimeters are in an inch?
There are 25.4 millimeters in 1 inch. To convert inches to millimeters, multiply the number of inches by 25.4.
What is 10 inches in mm?
10 inches is 254 millimeters.
How do you convert mm back to inches?
Multiply the number of millimeters by 0.0393701. 1 millimeter is 0.0393701 inches.
Is this inches to mm converter free?
Yes. It's free and works in any browser, even offline once the page has loaded. The answer updates as you type, and nothing you enter is sent anywhere.
Keep converting
Related converters
Start your first recording in seconds
It's free, it runs in your browser, and there's no account to create.
Start recording for free