Length converter
Convert Inches to Millimeters (in to mm)
1 in = 25.4 mm. Reading metric drawings on imperial machines and gauging stock.
Inches to millimeters conversion table
| in | mm |
|---|---|
| 1 in | 25.4 mm |
| 5 in | 127 mm |
| 10 in | 254 mm |
| 25 in | 635 mm |
| 50 in | 1270 mm |
| 100 in | 2540 mm |
| 250 in | 6350 mm |
How to convert inches to millimeters
Multiply the value in inches by 25.4 to get millimeters. 1 in equals 25.4 mm, and 1 mm equals 0.03937 in.
About these units
The inch is the base dimension unit on US engineering drawings, defined exactly as 25.4 millimeters. Shop tolerances are usually expressed in decimal inches rather than fractions.
The millimeter is one thousandth of a meter and the default dimension unit on metric engineering drawings. Machined tolerances are commonly quoted in hundredths of a millimeter.
Common questions
How many millimeters are in a inche?
1 in equals 25.4 mm.
How do you convert inches to millimeters?
Multiply the value in inches by 25.4 to get millimeters. 1 in equals 25.4 mm, and 1 mm equals 0.03937 in.