Millimetres to Inches
Convert millimetres (mm) to inches (in) instantly — with formula and reference table.
mm
in
Quick answer: 1 mm = 0.03937 in. To convert millimetres to inches, multiply by mm × 0.03937.
Converting millimetres to inches
This converter changes a value in millimetres (mm) into inches (in). One millimetre equals 0.03937 in. One inch is defined as exactly 25.4 millimetres, so converting millimetres to inches means dividing by 25.4. The conversion runs entirely in your browser — enter a value and the result updates instantly, in either direction.
Formula
in = mm × 0.03937
Example
Convert 10 mm to in: 10 × 0.03937 = 0.393701 in.
Millimetres to Inches conversion table
| Millimetres (mm) | Inches (in) |
|---|---|
| 1 mm | 0.03937 in |
| 2 mm | 0.07874 in |
| 3 mm | 0.11811 in |
| 5 mm | 0.19685 in |
| 10 mm | 0.393701 in |
| 20 mm | 0.787402 in |
| 25 mm | 0.984252 in |
| 50 mm | 1.968504 in |
| 100 mm | 3.937008 in |
How to use this converter
- Enter a value in the millimetres (mm) field.
- Read the converted value in inches (in) below.
- Type into the in field instead to convert in reverse, or use the swap button.
Frequently asked questions
How many inches are in a millimetre?
1 millimetre equals 0.03937 inches. Divide millimetres by 25.4 to get inches.
How do I convert 50 mm to inches?
50 divided by 25.4 = 1.97 inches.
Is the millimetre-to-inch factor exact?
Yes. The inch is defined as exactly 25.4 mm, so the conversion is exact.