Convert millimeter (mm) to inch (in).
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Inch to Millimeter Converter (in to mm)
Convert inch (in) to millimeter (mm).Unit Converter · Length
Quick answer
1 inch (in) is equal to 25.4 millimeters (mm). 1 millimeter (mm) is approximately equal to 0.03937008 inches (in).
To convert in to mm, multiply the value in inches by 25.4. For example, 10 in = 254 mm, and 100 in = 2,540 mm.
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Quick reference — inch to millimeter
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How to convert inches to millimeters
How many millimeters are in an inch? 1 inch is 25.4 millimeters. This free in to mm converter and inch to millimeter calculator gives the answer instantly for any value, and the same conversion is also written as inch to millimetre and inches to mm.
To convert inch (in) to millimeter (mm), multiply the value in inches by 25.4.
mm = in × 25.4
- 1
Take the value in inches
For example, 25 in.
- 2
Multiply by 25.4
25 × 25.4.
- 3
Read the answer in millimeters
25 in = 635 mm.
Inch to Millimeter conversion table
Common values from 1 to 1,000 inches converted to millimeters.
| Inch (in) | Millimeter (mm) |
|---|---|
| 1 in | 25.4 mm |
| 2 in | 50.8 mm |
| 3 in | 76.2 mm |
| 4 in | 101.6 mm |
| 5 in | 127 mm |
| 6 in | 152.4 mm |
| 7 in | 177.8 mm |
| 8 in | 203.2 mm |
| 9 in | 228.6 mm |
| 10 in | 254 mm |
| 15 in | 381 mm |
| 20 in | 508 mm |
| 25 in | 635 mm |
| Inch (in) | Millimeter (mm) |
|---|---|
| 30 in | 762 mm |
| 40 in | 1,016 mm |
| 50 in | 1,270 mm |
| 60 in | 1,524 mm |
| 70 in | 1,778 mm |
| 75 in | 1,905 mm |
| 80 in | 2,032 mm |
| 90 in | 2,286 mm |
| 100 in | 2,540 mm |
| 250 in | 6,350 mm |
| 500 in | 12,700 mm |
| 1,000 in | 25,400 mm |
About inches and millimeters
Inch (in)
An inch (in) is defined as exactly 2.54 centimeters, and 12 inches make a foot. It is still widely used for screen sizes and for pipe and tyre dimensions.
Millimeter (mm)
A millimeter (mm) is one thousandth of a meter. It is the smallest division on most rulers and tape measures.
in to mm: common questions
- How many millimeters are in 1 inch?
- 1 inch (in) is equal to 25.4 millimeters (mm). In short: 1 in = 25.4 mm.
- How do I convert inches to millimeters?
- To convert in to mm, multiply the value in inches by 25.4. For example, 5 in = 127 mm.
- How do I convert millimeters to inches?
- To convert mm to in, divide the value in millimeters by 25.4. Or open the Millimeter to Inch converter, which does it for you.
- What is 10 in in mm, and what is 100 in?
- 10 in = 254 mm, and 100 in = 2,540 mm. The table above lists more values from 1 to 1,000.
- Is this in to mm converter accurate?
- Yes. It uses the exact conversion factor and shows results to as many as 8 decimal places, so you can rely on it for study, work and everyday measuring.
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