Inches to Millimeters converter
Convert in to mm instantly. Type any value and get the result in millimeters. 1 in = 25.4 mm.
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1 in=
25.4mm
formula1 in = 25.4 mm
Common inches → millimeters
| = | 25.4 mm | |
| = | 50.8 mm | |
| = | 127 mm | |
| = | 254 mm | |
| = | 508 mm | |
| = | 1,270 mm | |
| = | 2,540 mm | |
| = | 12,700 mm | |
| = | 25,400 mm |
Need a different value? .
Convert the other way
Millimeters to Inches
How to convert inches to millimeters
To convert inches to millimeters, multiply the value by 25.4.
Formula
mm = in × 25.4
For example:
- →5 in = 127 mm
- →100 in = 2,540 mm
Quick reference
- ▸1 in = 25.4 mm
- ▸1 mm = 0.0393701 in
When you need to convert in to mm
- ·Clothing measurements — shirt length, pant inseam, fabric width.
- ·Height conversion — converting your height between metric and imperial systems.
- ·TV and monitor screen sizes — almost always quoted in inches.
- ·Paper sizes — A4 vs US Letter, photo print dimensions.
- ·Travel — reading road signs and distances abroad.
Frequently asked
How many millimeters are in 1 inche?
One inche equals 25.4 millimeters.
How do I convert in to mm in my head?
Multiply the value in inches by 25.4 to get millimeters.
What is the formula for inches to millimeters?
mm = in × 25.4.
What is the reverse — how many inches in 1 millimeter?
One millimeter equals 0.0393701 inches.
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