DailyCalc

Millimeters to Inches (mm to in)

1 mm ≈ 0.0393701 in. Type any value to convert it.

1 millimeter =

0.03937007874 in

inches

Conversion factor
1 mm ≈ 0.03937007874 in
Feet + inches
0 ft 0.04 in

Fix the highlighted field to update the result.

Show in all common units
1 mm in other units
UnitValue
millimeter (mm)1 mm
centimeter (cm)0.1 cm
meter (m)0.001 m
kilometer (km)0.000001 km
inch (in)0.03937007874 in
foot (ft)0.003280839895 ft
yard (yd)0.001093613298 yd
mile (mi)6.2137119 × 10⁻⁷ mi
nautical mile (nmi)5.399568 × 10⁻⁷ nmi

How to convert millimeters to inches

1 mm ≈ 0.0393701 in

1 in = 25.4 mm exactly (NIST SP 811), so inches = mm ÷ 25.4. One millimeter is about 0.03937008 in.

Examples

  • 6 mm = 0.23622047 in: A small drill bit sized in millimeters
  • 50 mm = 1.9685039 in: A pipe's outside diameter given in millimeters
  • 25 mm = 0.98425197 in: A day's rainfall reading

Mm to inches chart

Millimeters to inches
Millimeters (mm)Inches (in)
1 mm0.039370079 in
2 mm0.078740157 in
3 mm0.11811024 in
4 mm0.15748031 in
5 mm0.19685039 in
6 mm0.23622047 in
10 mm0.39370079 in
15 mm0.59055118 in
20 mm0.78740157 in
25 mm0.98425197 in
50 mm1.9685039 in
75 mm2.9527559 in
100 mm3.9370079 in

Common mistakes

  • Near-equivalent tool sizes are not identical: 6 mm is about 0.236 in, slightly smaller than 1/4 in (0.25 in).
  • Check the prefix: 25 mm is 2.5 cm, not 25 cm.

Frequently asked questions

How many inches is 1 mm?

About 0.03937 inches. Divide millimeters by 25.4, because an inch is exactly 25.4 mm.

What is 10 mm in inches?

About 0.394 inches, a little more than 3/8 inch (0.375 in). Metric sizes rarely land exactly on an inch fraction.

How do I convert mm to fractional inches?

Divide by 25.4, multiply the decimal by 16, and round to get sixteenths. For example, 6 mm is 0.236 in, about 4/16 or 1/4 inch.

Is 25 mm the same as 1 inch?

No. 25 mm is about 0.984 inches, since an inch is 25.4 mm. The 0.4 mm gap matters for tight fits.