MM to Inches Converter
Turn millimeters into inches for tooling, printing and DIY projects. There are 25.4 mm in an inch — type any figure to convert it live.
How to convert mm to inches
- Type a millimeter measurement into the box above.
- The inch equivalent appears immediately.
- Switch units with the dropdowns to convert mm to cm, meters or feet.
The formula
Inches come from dividing millimeters by 25.4:
inches = millimeters ÷ 25.4
Going back, multiply inches by 25.4 to return to millimeters.
Common mm to inches values
| Millimeters | Inches |
|---|---|
| 1 mm | 0.0394 in |
| 5 mm | 0.1969 in |
| 10 mm | 0.3937 in |
| 25.4 mm | 1 in |
| 50 mm | 1.9685 in |
| 100 mm | 3.937 in |
Related tools
- CM to Inches converter — for centimeter measurements.
- Inches to CM converter — the reverse direction.
Frequently asked questions
- How do I convert millimeters to inches?
- Divide the millimeters by 25.4. For instance, 50 mm ÷ 25.4 ≈ 1.9685 inches. The converter above shows the result instantly.
- How many millimeters are in an inch?
- There are exactly 25.4 millimeters in one inch (2.54 cm × 10).
- What is 10 mm in inches?
- 10 mm is about 0.3937 inches — a little over three-eighths of an inch.
- Why do so many specs use millimeters?
- Millimeters give fine resolution without decimals, which is why they dominate engineering drawings, phone dimensions, and hardware like screws and bolts.
- How do I read a millimeter value as a fraction of an inch?
- Convert to decimal inches first, then match to the nearest common fraction. For example 12.7 mm = 0.5 in exactly, which is one-half inch.
- Does this tool store what I enter?
- No — the calculation is done in your browser and nothing is transmitted or saved anywhere.