ToolNestInches to Millimeters Converter
Convert inches to millimeters instantly with our free length converter. 1 inch = 25.4 mm — type any value below and the result updates live.
Inches → Millimeters⇄ Swap: Millimeters → Inches
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Inches to Millimeters Formula
Millimeters = Inches × 25.4 (Inches = Millimeters × 0.03937)
Length conversion covers the metric units scientists and most of the world use (millimeters, centimeters, meters, kilometers) and the imperial units still standard in the United States (inches, feet, yards, miles).
Inches to Millimeters Conversion Table
| Inches | Millimeters | |
|---|---|---|
| 1 in | = | 25.4 mm |
| 2 in | = | 50.8 mm |
| 5 in | = | 127 mm |
| 10 in | = | 254 mm |
| 25 in | = | 635 mm |
| 50 in | = | 1,270 mm |
| 100 in | = | 2,540 mm |
About Inches and Millimeters
An inch is defined as exactly 2.54 centimeters. The US customary unit for screen sizes, rainfall, and everyday small measurements.
A millimeter is one-thousandth of a meter — about the thickness of a credit card. Engineers and machinists live in millimeters.
Frequently Asked Questions
How many millimeters are in one inch?
One inch equals 25.4 millimeters. Multiply any inches value by 25.4 to convert it.
What is the formula for converting inches to millimeters?
Millimeters = Inches × 25.4. To reverse it: inches = millimeters × 0.03937.
How do I convert millimeters back to inches?
Divide the millimeters value by 25.4 (equivalently, multiply by 0.03937). Or use our millimeters-to-inches converter going the other way.
Which is bigger, a inch or a millimeter?
A inch is bigger — one inch equals 25.4 millimeters.