Inch to Millimeter Converter
Convert Inch (in) to Millimeter (mm) instantly with this length converter. Use the calculator above, then check the formula, worked examples, table, and manual steps below.
Formula
mm = in à 25.4
Multiply the Inch value by 25.4 to get the equivalent value in Millimeter.
Example Conversions
1 Inch (in)
25.4 Millimeter (mm)
5 Inch (in)
127 Millimeter (mm)
10 Inch (in)
254 Millimeter (mm)
25 Inch (in)
635 Millimeter (mm)
100 Inch (in)
2540 Millimeter (mm)
Conversion Table
| Inch (in) | Millimeter (mm) |
|---|---|
| 0.1 | 2.54 |
| 0.5 | 12.7 |
| 1 | 25.4 |
| 2 | 50.8 |
| 5 | 127 |
| 10 | 254 |
| 25 | 635 |
| 50 | 1270 |
| 100 | 2540 |
| 250 | 6350 |
| 500 | 12700 |
| 1000 | 25400 |
How to Convert Manually
Use these steps to convert Inch values to Millimeter without the calculator.
- Write down the value in Inch (in) that you want to convert.
- Multiply that value by 25.4.
- For example, 10 Inch à 25.4 = 254 Millimeter.
- Label the result as Millimeter (mm).
Relative Size Comparison
This chart shows the visual difference in size between exactly one Inch and one Millimeter.
About Inch and Millimeter
Converting Inch to Millimeter is common in length applications, engineering, and everyday life. Whether you are translating specifications from international manuals, completing homework, or planning a project, having an accurate in to mm calculation ensures your measurements are correct.
The Inch is a unit of length. One Inch equals 0.0254 m in this converter's base scale.
The Millimeter is also a length unit. One Millimeter equals 0.001 m in the same base scale.
Precision and Rounding: When converting Inch to Millimeter, you may encounter long decimal numbers. For most practical purposes, rounding to two or three decimal places is sufficient. However, for machining, scientific research, or strict engineering tolerances, you should maintain as much precision as possible before your final calculation.
Worked Example
15 Inch equals 381 Millimeter.
15 in à 25.4 = 381 mm
FAQ
How do I convert Inch to Millimeter?
Multiply the Inch value by 25.4 to get the equivalent value in Millimeter.
What is the formula for Inch to Millimeter?
The formula is mm = in à 25.4.
How many Millimeter are in 1 Inch?
1 Inch equals 25.4 Millimeter.
Can I convert Millimeter back to Inch?
Yes. 1 Millimeter equals 0.03937007874 Inch, and the related converter can reverse the calculation.
What are common names for Inch and Millimeter?
Inch is shown as in and may also be searched as inches, ". Millimeter is shown as mm and may also be searched as millimetre, millimeters, millimetres.
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