Inches to Millimeters Converter
Convert Inches to Millimeters (in to mm) instantly, with the formula and a table of common values. Free, runs in your browser, nothing uploaded.
Everything happens on your own device. Nothing you type is ever sent anywhere.
Category
Result
25.4 mm
Formula
1 in = 25.4 mm
Common Inches to Millimeters Conversions
| Inches | Millimeters |
|---|---|
| 1 in | 25.4 mm |
| 2 in | 50.8 mm |
| 5 in | 127 mm |
| 10 in | 254 mm |
| 20 in | 508 mm |
| 50 in | 1,270 mm |
| 100 in | 2,540 mm |
| 500 in | 12,700 mm |
| 1,000 in | 25,400 mm |
This converter handles eight common unit categories - length, weight, temperature, volume, area, speed, data storage, and time - and updates the result instantly as you type, entirely in your browser. Most categories convert by a fixed ratio to a base unit (like meters for length or bytes for data), except temperature, which needs its own formula since 0°C isn't 0°F or 0 K.
Frequently asked questions
How do I convert Inches to Millimeters?
Multiply the value in in by 25.4: 1 in = 25.4 mm, so 10 in = 254 mm.
How do I convert Millimeters to Inches?
Multiply the value in mm by 0.0393701: 1 mm = 0.0393701 in, so 10 mm = 0.393701 in.
Is the value I enter sent anywhere?
No. The conversion runs entirely in your browser, so nothing you type ever leaves your device.