Millimeters to inches (mm to in)
The answer, the exact formula and a table with the values people look up most.
1 mm = 0.0393701 in1 in = 25.4 mmInches = Millimeters ÷ 25.4Example: 12 mm = 0.472441 in
1 mm = 0.03937007874 in
Conversions people ask for most
Convert millimeters to inches
| mm | in |
|---|---|
| 1 mm | 0.03937 in |
| 2 mm | 0.07874 in |
| 3 mm | 0.11811 in |
| 5 mm | 0.19685 in |
| 6 mm | 0.23622 in |
| 8 mm | 0.31496 in |
| 10 mm | 0.3937 in |
| 12 mm | 0.47244 in |
| 15 mm | 0.59055 in |
| 20 mm | 0.7874 in |
| 25 mm | 0.98425 in |
| 30 mm | 1.1811 in |
| 50 mm | 1.9685 in |
| 100 mm | 3.937 in |
The factor is exact: it comes from the official definition of the units. The table rounds to a few decimals; the converter above gives up to 10 significant digits.
The two units
Millimeter mm
A millimeter is one thousandth of a meter; it is the usual unit in technical drawings and engineering.
Inch in
An inch is exactly 2.54 centimeters by international agreement since 1959; it is used mainly in the United States and for screens and tires everywhere.
Frequently asked questions
How many inches are 12 millimeters?
12 mm = 0.472441 in.
What is the formula to convert millimeters to inches?
Inches = Millimeters ÷ 25.4. 12 mm = 0.472441 in.
Is this conversion exact?
Yes. The factor comes from the international definition of both units, so the only difference you may see is rounding.