Convert inches to mm
Inches to millimeters. Enter a value to convert, or use the inches to mm chart further down the page.
1 inch equals 25.4 millimeters. Going the other way, 1 millimeter = 0.03937007874 inches.
How to convert inches to mm
To convert inches to millimeters, multiply the inch value by 25.4. You can also divide by 0.03937007874 to get the same answer.
mm = in × 25.4
Worked example
Convert 15 in to millimeters:
15 in = 381 mm
inches to mm conversion chart
Use this inches to mm table for quick reference without typing anything.
| inches (in) | millimeters (mm) |
|---|---|
| 0.01 in | 0.254 mm |
| 0.1 in | 2.54 mm |
| 1 in | 25.4 mm |
| 2 in | 50.8 mm |
| 3 in | 76.2 mm |
| 5 in | 127 mm |
| 10 in | 254 mm |
| 20 in | 508 mm |
| 50 in | 1,270 mm |
| 100 in | 2,540 mm |
| 1,000 in | 25,400 mm |
Common inches to mm values
Ready-made answers for the inches to mm conversions people look up most often.
0.125 inches0.25 inches0.375 inches0.5 inches0.625 inches0.75 inches0.875 inches1 inches1.5 inches2 inches2.5 inches3 inches4 inches5 inches6 inches8 inches10 inches12 inches18 inches24 inches36 inches
What is a inch?
The inch has been defined as exactly 25.4 millimeters since the 1959 international yard and pound agreement. It is the base unit of the imperial and US customary length system and is still standard for screen sizes, pipe diameters and construction in the United States.
What is a millimeter?
The millimeter is a metric unit equal to one thousandth of a meter. It is the smallest unit marked on a standard metric ruler and is the working unit of engineering drawings, machining tolerances and rainfall measurement.
Frequently asked questions
How many mm are in an inch?
1 inches equals 25.4 mm. Going the other way, 1 mm is 0.03937007874 inches.
How do you convert inches to mm?
To convert inches to millimeters, multiply the inch value by 25.4. You can also divide by 0.03937007874 to get the same answer.
What is 10 inches in mm?
10 inches equals 254 mm. The conversion chart on this page lists the other values people look up most often.
Related length conversions
Convert inches to other units
- mm to inches
- inches to cm
- inches to meters
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- inches to feet
- inches to yards
- inches to miles
- inches to micrometers
- inches to nanometers
Convert other units to mm
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