Convert MM to Inches (mm to in)

Convert mm to inches instantly. 1 mm = 0.03937 in. Free mm-to-inches converter with table and formula.

Convert millimeters to inches instantly with this free online converter. One millimeter equals 0.03937 inches (1 mm = 0.03937 in). Type any value and the converted result appears immediately — no signup, and everything runs privately in your browser.

Millimeters are the standard unit in engineering drawings and manufacturing tolerances. The inch has been defined as exactly 2.54 centimeters since the international agreement of 1959. This conversion is used constantly for distance and length measurements in engineering, construction, travel, and everyday use. It bridges the metric system and the imperial/US customary system, which is why this conversion comes up so often.

Length Converter
All Conversions
Meters (m)0.001
Kilometers (km)1.000000e-6
Centimeters (cm)0.1
Millimeters (mm)1
Miles (mi)6.213712e-7
Yards (yd)0.001094
Feet (ft)0.003281
Inches (in)0.03937

Conversion formula

inches = millimeters × 0.03937

Conversion table

ValueConverted
1 mm0.03937 in
2 mm0.07874 in
5 mm0.19685 in
10 mm0.393701 in
25 mm0.984252 in
50 mm1.968504 in
100 mm3.937008 in

Frequently Asked Questions

How many inches are in a millimeter?

1 mm = 0.03937 in. So 10 millimeters equal 0.393701 inches.

How do you convert millimeters to inches manually?

Multiply the number of millimeters by 0.03937: inches = millimeters × 0.03937. For example, 10 mm × 0.03937 = 0.393701 in.

Is the mm to inches conversion exact?

Yes — both units have exact definitions, so the conversion itself is exact. The factor 0.03937 shown here is rounded for readability; the converter computes with full precision.

Is this mm to inches converter free and private?

Yes. It is completely free, requires no signup, and the conversion happens entirely in your browser — no values are sent to any server.