Millimeters to inches converter
Convert millimeters to inches with an editable calculator, worked example, formula and reference table. Check the unit definitions before you convert.
Updated · How we checkUse a decimal point, such as 2.5. Enter a value in mm; the result is in in.
Formula
Worked example
Convert 10 mm to in:
10 mm ≈ 0.3937007874 in
Multiply your mm value by the factor above. The calculator uses the full conversion factor before rounding the displayed answer.
Millimeters to inches table
Reference values rounded to 10 significant digits. Use the converter above for other amounts.
| Millimeters (mm) | Inches (in) |
|---|---|
| 0.1 | ≈ 0.003937007874 |
| 0.5 | ≈ 0.01968503937 |
| 1 | ≈ 0.03937007874 |
| 2 | ≈ 0.07874015748 |
| 5 | ≈ 0.1968503937 |
| 10 | ≈ 0.3937007874 |
| 25 | ≈ 0.9842519685 |
| 50 | ≈ 1.968503937 |
| 100 | ≈ 3.937007874 |
| 1000 | ≈ 39.37007874 |
Understanding millimeters
A millimeter is one thousandth of a meter. It is useful for small dimensions and material thickness.
Understanding inches
The international inch is exactly 0.0254 meters. Enter 2.5 for two and a half inches.
Precision and rounding
The calculator keeps decimal precision during the conversion. Displayed values use up to 10 significant digits; an approximation sign marks the reference results. Keep extra digits until your final measurement or purchase decision.
References
Definitions and method references. Example rates and prices on this page are editable assumptions.