MM to Inches Converter
Convert millimeter to inch instantly. 1 mm = 0.03937007874 in, worked steps and a full reference table.
How to use it
- Type the value in millimeter — the result updates as you type.
- Use Swap to flip the direction, or change either dropdown to convert between any two units.
- Click the result to copy it. The URL updates too, so you can bookmark or share the exact conversion.
Examples
| 1 mm | 0.03937007874 in |
| 5 mm | 0.1968503937 in |
| 10 mm | 0.3937007874 in |
| 100 mm | 3.937007874 in |
One millimeter equals 0.039370079 inches (in). To convert millimeters to inches, multiply by 0.039370079; to go back the other way, multiply by 25.4 instead.
The converter above does it as you type and shows the working underneath, so you can check the arithmetic rather than take the number on trust.
What millimeters and inches actually measure
Millimeter (mm) — A millimetre is a thousandth of a metre, and the smallest division on a normal ruler. Engineering drawings, timber and steel sizes, rainfall and screen bezels.
Inch (in) — An inch is exactly 25.4 millimetres by international agreement since 1959. Screen sizes, pipe and tyre diameters, and construction in the US.
MM to Inches conversion table
The most common values, worked out in advance. Anything not listed can be typed straight into the converter.
| mm | in |
|---|---|
| 1 mm | 0.039370079 in |
| 2 mm | 0.078740157 in |
| 5 mm | 0.19685039 in |
| 10 mm | 0.39370079 in |
| 25 mm | 0.98425197 in |
| 50 mm | 1.9685039 in |
| 100 mm | 3.9370079 in |
How to convert millimeters to inches by hand
Multiply the number of millimeters by 0.039370079.
For example, 25 mm × 0.039370079 = 0.98425197 in.
Going the other way, divide by 0.039370079 — or multiply by 25.4, which is the same thing and easier to do in your head.
Everything runs in your browser
There is no server involved in the calculation. The numbers you type never leave your device, nothing is logged, and the page keeps working with no connection once it has loaded. That is not a marketing line — it is simply how the tool is built, because a calculation like this has no reason to touch a network.
Questions people ask
How many in are in 1 mm?
1 mm equals exactly 0.03937007874 in. Multiply any value in millimeter by 0.03937007874 to get inch.
Is anything uploaded to a server?
No. The whole calculation happens in your browser. Nothing is sent anywhere, and the page keeps working offline once loaded.
Also searched for
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Last updated 18 August 2026