Millimeters to Inches Converter (mm to in)

Type a value in millimeters to see it in inches instantly.

1 millimeter (mm) = 0.0393700787 inches (in)

1 inch (in) = 25.4 millimeters (mm)

Millimeters (mm)

Inches (in)

10 mm = 0.3937007874 in

Open in the full converter to compare with other length units.

How to convert millimeters to inches

Multiply the number of millimeters by 0.0393700787, or divide by 25.4.

in = mm × 0.0393700787 (or mm ÷ 25.4)

Example: 10 mm × 0.0393700787 = 0.393701 in

Common drill-bit and wrench equivalents: 3 mm ≈ 1/8 in, 6 mm ≈ 1/4 in, 13 mm ≈ 1/2 in and 19 mm ≈ 3/4 in. They are close but not identical, so a metric bolt will not always fit an imperial wrench.

mm to in conversion table

Millimeters (mm)	Inches (in)
1 mm	0.0393701 in
2 mm	0.0787402 in
3 mm	0.11811 in
4 mm	0.15748 in
5 mm	0.19685 in
6 mm	0.23622 in
8 mm	0.314961 in
10 mm	0.393701 in
12 mm	0.472441 in
13 mm	0.511811 in
15 mm	0.590551 in
16 mm	0.629921 in
19 mm	0.748031 in
20 mm	0.787402 in
22 mm	0.866142 in
25 mm	0.984252 in
25.4 mm	1 in
30 mm	1.1811 in
40 mm	1.5748 in
50 mm	1.9685 in
100 mm	3.93701 in

About the units

Millimeter (mm)

A millimeter (millimetre) is one thousandth of a meter. Engineering drawings, rainfall and fastener sizes are usually given in millimeters.

Inch (in)

Since 1959 the international inch has been defined as exactly 2.54 centimeters. It is used in the US and UK for screen sizes, tools, timber and many manufactured parts.

Frequently asked questions

How many inches are in 1 millimeter?

1 millimeter equals 0.0393700787 inches.

How do I convert millimeters to inches?

Multiply the number of millimeters by 0.0393700787, or divide by 25.4. For example, 10 mm × 0.0393700787 = 0.393701 in.

How many millimeters are in 1 inch?

1 inch equals 25.4 millimeters.

How many mm are in an inch?

There are exactly 25.4 millimeters in one inch.

Related conversions

Background reading: Metric vs. Imperial.