What is the Inches to MM Converter?
Convert inches to millimetres instantly, with the conversion factor and a table of other units.
Results update as you type, and nothing you enter leaves your device.
How it is calculated
millimetres = inches × 25.4
How to use it
- Fill in the fields at the top of the page.
- Read the result in the results panel. It updates as you type.
- Change any value to compare scenarios, or use Share to send the result as a link.
Common questions
How do I convert inches to millimetres?
Multiply the value in inches by 25.4. For example, 10 inches = 254 millimetres.
How do I convert millimetres back to inches?
Divide by 25.4, or press the swap button between the two unit boxes.
What formula does the Inches to MM Converter use?
It uses: millimetres = inches × 25.4.
Is the Inches to MM Converter free, and is my data stored?
It is free with no sign-up. The calculation runs in your browser, so the values you enter are not sent to or stored on our server.