Millimeters to inches
Type a value in millimeters to see it in inches straight away, or type in the second box to convert back.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Type the value in the millimeters box.
- Read the result in inches as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
in = mm × 0.03937007874
Multiply the value in millimeters by 0.03937007874 to get inches.
Example
To convert 25 mm to inches: 25 × 0.03937007874 = 0.984252 in.
Conversion table
| Millimeters (mm) | Inches (in) |
|---|---|
| 1 | 0.0393701 |
| 2 | 0.0787402 |
| 3 | 0.11811 |
| 5 | 0.19685 |
| 10 | 0.393701 |
| 20 | 0.787402 |
| 25 | 0.984252 |
| 50 | 1.9685 |
| 100 | 3.93701 |
| 250 | 9.84252 |
| 500 | 19.685 |
| 1,000 | 39.3701 |
About the units
- Millimeter
- A millimeter is one thousandth of a meter, common in engineering drawings and thickness measurements.
- Inch
- An inch is exactly 2.54 centimeters under the 1959 agreement, used for screens, tyres and pipes.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many inches are in one millimeter?
1 mm = 0.0393701 in exactly.
How do I convert millimeters to inches?
Use in = mm × 0.03937007874. For example, 25 mm = 0.984252 in.
How many millimeters are in one inch?
1 in = 25.4 mm.
Are the inch, foot and mile factors exact or rounded?
They are exact by definition. Since the 1959 agreement one inch is exactly 2.54 cm, one foot 0.3048 m and one mile 1609.344 m.
What is the difference between a mile and a nautical mile?
A statute mile is 1609.344 meters and is used on roads. A nautical mile is 1852 meters and is used at sea and in aviation.