mm to inch Converter - Millimeter to Inch

Millimeter (mm) to Inch (in) (inch)

Direct answer

1 mm = 0.03937007874 inch

inch = mm × 0.03937007874

Converter

Input

Result

0.03937007874inch

inch = mm × 0.03937007874

mm = inch × 25.4

Example: 10 mm = 10 × 0.03937007874 = 0.393700787402 inch.

Express both mm and inch in the same base unit m (meter), then cancel the shared base unit.

1
Rewrite mm in the base unit
$1 mm = 0.001 m$
2
Rewrite inch in the base unit
$1 inch = 0.0254 m$
3
Forward conversion
$1 mm = \frac{0.001 m}{0.0254 m} \times 1 inch = \frac{0.001}{0.0254} inch = 0.03937007874 inch$
4
Reverse conversion
$1 inch = \frac{0.0254 m}{0.001 m} \times 1 mm = \frac{0.0254}{0.001} mm = 25.4 mm$

A guarded explanation for this pair page covering definition, principle, assumptions, and cautions.

Guarded output

AI text is for interpretation only. The page calculator remains the source of truth for numeric results.

1 mm = 0.03937007874 inch.

10 mm = 0.393700787402 inch.

100 mm = 3.93700787402 inch.

Use inch = mm × 0.03937007874.

1 inch = 25.4 mm.

Use the conversion factor and round the result to the precision required by your calculation.