About the Millimeters to Inches Converter
Convert millimeters (mm) to inches (in) instantly. Includes the exact conversion factor, formula and a quick reference table.
Also known as: mm to in, Millimeters to Inches, convert Millimeters to Inches, mm to in, millimeters to inches, mm to in.
How to use this calculator
- Enter value in millimeters.
- The result updates instantly as you type — press Calculate (or Enter) at any time.
- Open “Step-by-step” to see how the answer was worked out.
- Use Copy result or Share to save the answer or send a link with your inputs.
Formula
in = mm × 0.0393700787
Worked example
Using the values pre-filled in the calculator above:
- Value in millimeters = 25 mm
the calculator returns:
- Inches: 0.984252 in
- Nanometers: 25,000,000 nm
- Micrometers: 25,000 µm
- Centimeters: 2.5 cm
Working
25 mm × 0.0393700787 = 0.98425197 in