Convert Inches to Millimeters

Enter the value in inches to get its exact equivalent in millimeters instantly.

How to convert inches to millimeters?

To transform a measurement from inches (in) to millimeters (mm), multiply the value by the exact conversion factor of 25.4. The formula is:

mm = in × 25.4

The international inch was standardized in 1959 as exactly 25.4 millimeters. This unit is essential in industrial sectors, tool sizing, and electronic components.

Inches (in) Millimeters (mm)
1.00 25.40
5.00 127.00
10.00 254.00
50.00 1,270.00
100.00 2,540.00

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Frequently Asked Questions

How many millimeters are in 1 inch?

There are exactly 25.4 millimeters in one international inch.

How much is 1/2 inch in mm?

It is 12.7 millimeters, calculated by multiplying 0.5 by 25.4.