Millimeters to Inches Converter

Convert Millimeters (mm) to Inches (in) instantly — free length converter, no sign-up.

Conversion formula

1 mm (millimeters) = 0.03937 in (inches)

in = mm × 0.03937

Worked example

To convert 25 millimeters to inches, multiply by 0.03937 (25 × 0.03937) — which gives 0.984252 in.

Common millimeters to inches values

MillimetersInches
1 mm0.03937 in
2 mm0.07874 in
5 mm0.19685 in
10 mm0.393701 in
25 mm0.984252 in
50 mm1.9685 in
100 mm3.937 in
500 mm19.685 in
1000 mm39.3701 in

About length conversion

Length conversions move between the metric system (millimetres, centimetres, metres, kilometres), which is decimal and scales by powers of ten, and the imperial/US customary system (inches, feet, yards, miles), which does not. The metre is the SI base unit and every conversion here is defined against it: the inch has been exactly 25.4 mm since the 1959 international yard and pound agreement, which is why these factors are exact rather than approximate.

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