Inch to Millimetre Converter
Convert inch to millimetre instantly with a local, precise conversion. Enter decimals, zero, negative values where meaningful, or scientific notation.
How to convert inch to millimetre
1 in = 25.4 mm. Convert through metre.
Worked examples
2 in equals 50.8 mm. Enter any valid finite value above for an immediate result.
Inch to Millimetre conversion table
| Inch (in) | Millimetre (mm) |
|---|---|
| 1 in | 25.4 mm |
| 2 in | 50.8 mm |
| 5 in | 127 mm |
| 10 in | 254 mm |
| 20 in | 508 mm |
| 25 in | 635 mm |
| 50 in | 1,270 mm |
| 100 in | 2,540 mm |
Reverse conversion: Millimetre to Inch Converter
Frequently asked questions
How do I convert inch to millimetre?
1 in = 25.4 mm. Convert through metre.
Can I enter decimals or scientific notation?
Yes. The converter accepts decimals, grouped numbers and scientific notation, then formats the result without changing the underlying calculation.
Is this conversion performed online?
The page is delivered by the website, but the value conversion itself runs locally in your browser and is not submitted to a calculation service.