Length converter
Inches to MM Converter
Convert inches to millimeters for parts, product dimensions, tools, and technical measurements.
Free Browser-only No sign-up Instant formula
US and Imperial volume units are different. Make sure you select the correct gallon, pint, or fluid ounce.
Length
Enter a number to convert.
Formula Formula appears here.
Calculation Calculation appears here.
Precision Auto
Inches to MM Formula
millimeters = inches × 25.4
Example Conversions
| Input | Output |
|---|---|
| 1 in | 25.4 mm |
| 0.5 in | 12.7 mm |
| 12 in | 304.8 mm |
Related Conversion Links
Frequently Asked Questions
How many millimeters are in 1 inch?
1 inch equals exactly 25.4 millimeters.
How do I convert inches to millimeters?
Multiply inches by 25.4.
Is this converter free?
Yes. This converter is free to use and does not require sign-up.
Are my values uploaded to a server?
No. The conversion runs in your browser. Values are not sent to a server.
Can I copy the result?
Yes. Use the copy buttons to copy the result, formula, or a shareable result with formula.