Formula
in to mm conversion formula
Use this relationship for a direct conversion:
mm = in x 25.4
Worked example
2 in = 50.8 mm.
Pixel conversions assume 96 pixels per inch. Use actual device or print PPI when physical pixel size matters.
Typography and Screen Length conversion
Convert Inch to Millimeter
1 inch (in) equals 25.4 millimeter (mm). Enter any value below to convert from in to mm.
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1 in = 25.4 mm
All Typography units
From 1 in| Unit | Value |
|---|---|
| Inch in | 1 |
| CSS pixel (96 PPI) px | 96 |
| Point pt | 72 |
| Pica pc | 6 |
| Millimeter mm | 25.4 |
| Centimeter cm | 2.54 |
| Twip twip | 1,440 |
Recent conversions
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Quick reference
Inch to Millimeter table
| Inch (in) | Millimeter (mm) |
|---|---|
| 0.01 | 0.254 |
| 0.1 | 2.54 |
| 1 | 25.4 |
| 2 | 50.8 |
| 5 | 127 |
| 10 | 254 |
| 25 | 635 |
| 50 | 1,270 |
| 100 | 2,540 |
| 1,000 | 25,400 |
From unit
About the inch
The physical reference length, exactly 25.4 millimeters.
Symbol: in
To unit
About the millimeter
One thousandth of a meter.
Symbol: mm
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Conversion standard
Definitions are checked against CSS Values and Units Level 4. Calculations use full internal precision before display rounding.
View the complete typography and screen length converterQuestions
in to mm FAQ
How do you convert inch to millimeter?
Use the formula mm = in x 25.4. 1 inch (in) equals 25.4 millimeter (mm).
Is the in to mm conversion exact?
Both unit definitions use exact factors. Only the displayed decimal may be rounded.