Convert Millimetre to Inch
Turn Millimetres into inches in an instant. Type a value below to get an accurate mm → in result, with the formula and a quick-reference table.
1 mm = 0.039370079 in
Quick answer: 1 Millimetre = 0.039370079 Inch
Millimetre to Inch conversion table
| Millimetre (mm) | Inch (in) |
|---|---|
| 1 mm | 0.039370079 in |
| 2 mm | 0.078740157 in |
| 5 mm | 0.19685039 in |
| 10 mm | 0.39370079 in |
| 20 mm | 0.78740157 in |
| 50 mm | 1.9685039 in |
| 100 mm | 3.9370079 in |
| 500 mm | 19.685039 in |
| 1,000 mm | 39.370079 in |
How to convert Millimetre to Inch
To convert Millimetres to inches, multiply the value by 0.039370079.
- Take your measurement in Millimetres.
- Multiply it by 0.039370079 — the number of inches in one Millimetre.
- The result is the same amount, expressed in inches.
To go the other way, multiply inches by 25.4 — or simply divide by 0.039370079.
For example, a sharp pencil tip is about 0.5 mm, which is 0.019685039 in.
About Millimetre and Inch
A millimetre is one-thousandth of a metre (1/1000 m) — the smallest line printed on a standard ruler. It is the everyday unit for fine measurements such as engineering tolerances, screw threads, paper thickness and rainfall.
An inch is an imperial unit of length defined as exactly 2.54 centimetres, or one-twelfth of a foot. It is standard in the United States for screen sizes, lumber, pipe diameters and everyday measurements.
The Millimetre is a metric unit while the Inch comes from the imperial / US customary system — which is exactly why this conversion comes up so often. One Millimetre equals 0.039370079 inches.
Other length conversions
Frequently asked questions
How many inches are in a Millimetre?
1 Millimetre equals 0.039370079 Inch (mm → in). To convert any amount, multiply the number of Millimetres by 0.039370079.
How do I convert Millimetre to Inch?
Enter the number of Millimetres in the converter above and read the result in inches. It applies the exact mm → in factor instantly, with full precision.
Is the Millimetre to Inch converter free?
Yes — it is completely free and unlimited, needs no sign-up, and runs right in your browser, so it is instant and private.
Is the conversion accurate?
Yes. It uses the internationally defined length factors and full floating-point precision, then rounds the display to a clean, readable number.