How to convert inches to millimeters
To convert inches (in) to millimeters (mm), multiply the value in inches by 25.4.
mm = in × 25.4
Example: 10 in = 254 mm.
You can also type 10 in to mm into the smart calculator, or mix units: 1 in + 1 mm.
Inches to Millimeters conversion table
| Inches | Millimeters |
|---|---|
| 0.01 in | 0.254 mm |
| 0.1 in | 2.54 mm |
| 0.25 in | 6.35 mm |
| 0.5 in | 12.7 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 |
| 12 in | 304.8 mm |
| 15 in | 381 mm |
| 20 in | 508 mm |
| 25 in | 635 mm |
| 30 in | 762 mm |
| 40 in | 1,016 mm |
| 50 in | 1,270 mm |
| 60 in | 1,524 mm |
| 75 in | 1,905 mm |
| 100 in | 2,540 mm |
| 250 in | 6,350 mm |
| 500 in | 12,700 mm |
| 1,000 in | 25,400 mm |
Converting millimeters back to inches
1 mm = 0.03937007874 in. See the Millimeters to Inches converter, or press the swap button above.
About the units
Inch (in)
Exactly 2.54 centimeters. Twelve inches make a foot.
Millimeter (mm)
One thousandth of a meter. Ten millimeters make a centimeter.
Length measures distance in one dimension. The SI base unit is the meter, defined by the distance light travels in a vacuum in 1/299,792,458 of a second. Since the 1959 international yard and pound agreement, imperial and US customary lengths are defined exactly in meters: an inch is exactly 2.54 centimeters.
Questions and answers
How many millimeters are in a inch?
One inch (in) equals 25.4 millimeters (mm).
How do I convert inches to millimeters?
To convert inches to millimeters, multiply the value in inches by 25.4. The formula is mm = in × 25.4. For example, 10 in = 254 mm.
What is 10 in in mm?
10 inches is 254 millimeters.
Which is bigger, a inch or a millimeter?
A inch is bigger: 1 in = 25.4 mm.
How many centimeters are in a foot?
A foot is exactly 30.48 centimeters, because an inch is defined as exactly 2.54 cm and a foot is 12 inches.
Does this in to mm converter work offline?
Yes. ConvertEasy is a progressive web app: after your first visit it keeps working with no connection, and you can install it to your home screen from the browser menu.