Millimeters to Inches Converter
One Millimeter equals 0.03937007874 Inches (1 mm = 0.03937007874 in). Multiply a Millimeter value by 0.03937007874 to get the equivalent in Inches. Use the calculator above for your value, or check the examples and reference table below.
Formula
in = mm × 0.03937007874
Multiply the Millimeter value by 0.03937007874 to get the equivalent value in Inches.
Example Conversions
1 Millimeter (mm)
0.03937007874 Inch (in)
5 Millimeter (mm)
0.1968503937 Inch (in)
10 Millimeter (mm)
0.3937007874 Inch (in)
25 Millimeter (mm)
0.9842519685 Inch (in)
100 Millimeter (mm)
3.937007874 Inch (in)
Conversion Table
| Millimeter (mm) | Inch (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 |
| 250 | 9.842519685 |
| 500 | 19.68503937 |
| 1000 | 39.37007874 |
How to Convert Manually
Use these steps to convert Millimeter values to Inch without the calculator.
- Write down the value in Millimeter (mm) that you want to convert.
- Multiply that value by 0.03937007874.
- For example, 10 Millimeters × 0.03937007874 = 0.3937007874 Inches.
- Label the result as Inch (in).
Relative Size Comparison
This chart shows the visual difference in size between exactly one Millimeter and one Inch.
About Millimeter and Inch
The millimeter is one thousandth of a meter. Engineering and manufacturing drawings in metric countries are dimensioned almost exclusively in millimeters to avoid decimal points. The inch is defined as exactly 25.4 millimeters, one twelfth of a foot. Screen sizes, pipe diameters, and US manufacturing drawings are specified in inches. One Millimeter equals 0.03937007874 Inches (1 mm = 0.03937007874 in). Millimeter is used in engineering and CAD drawings and in manufacturing tolerances. Inch is used in screen and display sizes.
Precision and Rounding:Length factors between metric and imperial units are exact by definition (1 ft = 0.3048 m since 1959), so any rounding error comes from display precision, not the factor. Two or three decimal places suit carpentry and DIY work; machining and surveying often require four or more.
Conversion factors per NIST Special Publication 811 and the BIPM SI Brochure (9th edition) (reference).
Worked Example
15Millimeters equals0.5905511811Inches.
15 mm × 0.03937007874 = 0.5905511811 in
FAQ
How do I convert Millimeter to Inch?
Multiply the Millimeter value by 0.03937007874 to get the equivalent value in Inches.
What is the formula for Millimeter to Inch?
The formula is in = mm × 0.03937007874.
How many Inches are in 1 Millimeter?
1 Millimeter equals 0.03937007874 Inches.
Can I convert Inch back to Millimeter?
Yes. 1 Inch equals 25.4 Millimeters, and the related converter can reverse the calculation.
What are common names for Millimeter and Inch?
Millimeter is shown as mm and may also be searched as millimetre, millimeters, millimetres. Inch is shown as in and may also be searched as inches, ".
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