Length Converter
Result
... Inch = ... Millimeter
Find the units to convert
Inch to Millimeter Converter
Use this page to convert inch values into millimeter, with background details, formulas, a worked example, and a quick conversion table.
Conversion formula
1 in = 25.4 mm
1 mm = 0.0393700787401575 in
Example: 15 in = 381 mm
Inch
An inch is defined as exactly 25.4 millimeters.
History: The inch comes from older customary systems and was standardized internationally in 1959.
Current use: Inches are still used for screens, hardware, and consumer products.
Also written as in, inches, ".
Millimeter
A millimeter is 1/1,000 of a meter in the SI system.
History: It became widely used with metric manufacturing and engineering tolerances.
Current use: Millimeters are common in product specs, machining, and technical drawings.
Also written as mm, millimeters, millimetre, millimetres.
Inch to Millimeter table
| Inch [in] | Millimeter [mm] |
|---|
| 0.01 in | 0.254 mm |
| 0.1 in | 2.54 mm |
| 1 in | 25.4 mm |
| 2 in | 50.8 mm |
| 5 in | 127 mm |
| 10 in | 254 mm |
| 20 in | 508 mm |
| 50 in | 1,270 mm |
| 100 in | 2,540 mm |
Frequently asked questions
How many Millimeter (mm) are in one Inch (in)?
One Inch equals 25.4 Millimeter.
How do you convert Inch to Millimeter?
Multiply the Inch value by 25.4 to get the result in Millimeter.
How do you convert Millimeter back to Inch?
Multiply the Millimeter value by 0.0393700787401575 to get back to Inch.
What is 15 Inch in Millimeter?
15 Inch equals 381 Millimeter.
