How to convert millimeters to inches
One millimeter equals 0.03937 inches. To convert, multiply the number of millimeters by 0.03937 (or divide by 25.4):
Mental-math shortcut: 25.4 mm is exactly one inch. Handy approximations: 3 mm ≈ 1/8 in, 6 mm ≈ 1/4 in, 13 mm ≈ 1/2 in, 19 mm ≈ 3/4 in.
Example
Convert 25 millimeters to inches: 25 mm × 0.03937 = 0.984252 in.
Millimeters to Inches conversion chart
| Millimeters (mm) | Inches (in) |
|---|---|
| 1 | 0.03937 |
| 2 | 0.07874 |
| 3 | 0.11811 |
| 4 | 0.15748 |
| 5 | 0.19685 |
| 6 | 0.23622 |
| 8 | 0.314961 |
| 10 | 0.393701 |
| 12 | 0.472441 |
| 15 | 0.590551 |
| 20 | 0.787402 |
| 25 | 0.984252 |
| 30 | 1.1811 |
| 50 | 1.9685 |
| 100 | 3.937 |
What is a millimeter?
A millimeter (mm) is one thousandth of a meter. It is used for small, precise measurements such as screw and drill-bit sizes, jewelry, rainfall, camera lenses and engineering drawings. There are 10 millimeters in a centimeter and exactly 25.4 millimeters in an inch.
What is an inch?
An inch (in or ″) is a unit of length in the US customary and imperial systems. Since 1959 it has been defined as exactly 2.54 centimeters. There are 12 inches in a foot, and inches are used for screen sizes, height, rainfall and construction in the United States.
Converting the other way? Use the Inches to Millimeters converter.
Frequently asked questions
How many inches is one millimeter?
One millimeter is 0.03937 inches.
How do I convert millimeters to inches?
Multiply the value in millimeters by 0.03937. For example, 25 mm × 0.03937 = 0.984252 in.
What is 10 mm in inches?
10 mm is 0.393701 inches.
How do I convert inches to millimeters?
Multiply inches by 25.4 (or divide by 0.03937). You can also use our Inches to Millimeters converter.
Conversions use the internationally agreed definitions of each unit (for example, 1 inch = 2.54 cm exactly) and are rounded for display. Volume converters use US customary units unless stated otherwise.
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