Marks Calc

inches to millimeters

Convert inch to millimeter — instant, free, with the formula shown.

1 in=25.4 mm

How to convert inch to millimeter

To convert inch to millimeter, multiply by 25.4:

mm = in × 25.4

For example, 10 in × 25.4 = 254 mm.

in to mm conversion table

inches (in)millimeters (mm)
1 in25.4 mm
2 in50.8 mm
5 in127 mm
10 in254 mm
25 in635 mm
50 in1270 mm
100 in2540 mm
250 in6350 mm
500 in12700 mm
1000 in25400 mm
Reverse: Millimeter to Inch

Other inch conversions

Convert to millimeter from another unit

in to mm — frequently asked

How many millimeters are in 1 inch?

1 inch = 25.4 millimeters (in × 25.4 = mm).

What is the formula to convert inch to millimeter?

Multiply your inch value by 25.4 to get millimeter.

How do I convert 10 inches to millimeters?

10 in = 254 mm. For 100 in the answer is 2540 mm. Use the calculator on this page for any other value.

When to convert inch to millimeter

1Engineering and construction (mm to feet, meters to inches)
2Running, cycling and athletics (km to miles, miles to yards)
3International shipping and travel (nautical miles, kilometers)
4Manufacturing tolerances (micrometers and nanometers)

Length conversion — common questions

How many feet are in 1 meter?

1 meter equals approximately 3.2808 feet. The exact conversion factor is 1 ft = 0.3048 m.

How do I convert kilometers to miles?

Multiply the kilometer value by 0.621371. For example, 10 km × 0.621371 ≈ 6.2137 miles.

Is 1 yard exactly 3 feet?

Yes. By definition 1 yard = 3 feet = 36 inches = 0.9144 meters.

See all length converters