Length conversion

Inches to Millimeters

Convert fastener sizes, material thicknesses, and equipment dimensions from inches to precise millimeter values.

Inches

1 in

Millimeters

25.4 mm

mm = in × 25.4

The formula

How to convert inches to millimeters

Apply mm = in × 25.4. For example, 0.125 in equals 3.175 mm.

Precision

Accurate constants, readable results

OmniUnit calculates with the full stored conversion factor, then displays up to 12 significant digits.

Common inches conversions

InchesMillimeters
0.125 in3.175 mm
0.25 in6.35 mm
0.5 in12.7 mm
1 in25.4 mm
2 in50.8 mm
10 in254 mm

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