How to use Inches to MM
- Type a value in inches.
- The result in millimeters appears instantly.
- Type in the second box to convert the other way.
How to convert inches to millimeters
Multiply the value in inches by 25.4. Formula: mm = in × 25.4. Example: 10 in × 25.4 = 254 mm.
Common inches to millimeters conversions
5 in = 127 mm. 25 in = 635 mm. 50 in = 1,270 mm. 100 in = 2,540 mm.
Where is in to mm conversion used?
Length conversions come up constantly when metric and imperial systems meet: checking your height for a visa or medical form, comparing screen and TV sizes, buying furniture or clothes from another country, reading product dimensions on international shopping sites, and following DIY or engineering drawings.
What are inches?
An inch is exactly 2.54 centimeters by international agreement. It is used in the US and UK for screens, height and small dimensions.
What are millimeters?
A millimeter is one thousandth of a meter. It is used for small, precise measurements like screw sizes, rainfall and phone thickness.
Inches to millimeters conversion table
| Inches (in) | Millimeters (mm) |
|---|---|
| 1 | 25.4 |
| 2 | 50.8 |
| 3 | 76.2 |
| 4 | 101.6 |
| 5 | 127 |
| 6 | 152.4 |
| 7 | 177.8 |
| 8 | 203.2 |
| 9 | 228.6 |
| 10 | 254 |
| 12 | 304.8 |
| 15 | 381 |
| 20 | 508 |
| 25 | 635 |
| 30 | 762 |
| 50 | 1,270 |
| 75 | 1,905 |
| 100 | 2,540 |
Frequently asked questions
How many millimeters are in 1 inch?
1 inch = 25.4 millimeters (1 in = 25.4 mm).
How many inches are in 1 millimeter?
1 millimeter = 0.03937 inches (1 mm = 0.03937 in).
What is 10 in in millimeters?
10 in = 254 mm.
What is 100 in in millimeters?
100 in = 2,540 mm.
Is the in to mm conversion exact?
Yes. Since 1959 the inch has been defined as exactly 2.54 cm, so every imperial–metric length factor (inch, foot, yard, mile) is exact. Results here are rounded only for display.
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