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Millimeters to inches (mm to in)

1 mm = 0.03937007874 in. Enter any value below to convert millimeters to inches instantly, or use the length converter for every other unit.

Maintained by Jairo TunisseLast updated Editorial policy

1 mm = 0.03937007874 in

in = mm × 0.03937007874
1 in = 25.4 mm

Convert length

Common length conversions

1 in2.54 cm
1 ft0.3048 m
1 yd0.9144 m
1 mi1.609344 km
1 nmi1.852 km
1 m3.280839895 ft
1 km0.6213711922 mi
1 cm0.3937007874 in

Millimeters to inches conversion table

Millimeters to inches
Millimeters (mm)Inches (in)
1 mm0.03937007874 in
3 mm0.1181102362 in
5 mm0.1968503937 in
6 mm0.2362204724 in
8 mm0.3149606299 in
10 mm0.3937007874 in
12 mm0.4724409449 in
19 mm0.7480314961 in
25 mm0.9842519685 in
50 mm1.968503937 in
100 mm3.937007874 in

The formula

in = mm × 0.03937007874

1 mm = 0.001 m. 1 in = 0.0254 m (exact). These are exact definitions, so the only rounding is in the displayed result (10 significant digits).

When you need it

Millimeters to inches matters for drill bits, bolts, plywood thickness, jewelry and rainfall. Since 1 inch is exactly 25.4 mm, divide by 25.4. Note that metric and fractional-inch tools rarely match exactly: a 6 mm bit is slightly smaller than a 1/4-inch bit.

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Frequently asked questions

How do I convert millimeters to inches?

Multiply the value in millimeters by 0.03937007874 (or divide by 25.4). For example, 6 mm = 0.2362204724 in.

How many inches are in one millimeter?

1 mm = 0.03937007874 in.

What is 1/4 inch in mm?

Exactly 6.35 mm, because a quarter of 25.4 mm is 6.35 mm.

Can I swap a metric wrench for an inch one?

Only when the sizes nearly coincide (for example 19 mm and 3/4 in). Most pairs differ enough to round off a fastener.

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