Millimeters to Inches (mm to in)
1 millimeter = 0.03937008 inches
How to convert millimeters to inches
in = mm ÷ 25.4
Example: 5 ÷ 25.4 = 0.1969, so 5 millimeters = 0.1969 inches.
Millimeters to inches is common in workshops and DIY: drill bits, bolts, wrench sizes and lumber thicknesses are often listed in one system while your tools use the other.
Exactly 25.4 mm make an inch, so 6 mm ≈ 1/4 in, 13 mm ≈ 1/2 in and 19 mm ≈ 3/4 in — the nearest fractional sizes used on imperial tools.
Millimeters to Inches conversion table
| Millimeters (mm) | Inches (in) |
|---|---|
| 1 mm | 0.0394 in |
| 2 mm | 0.0787 in |
| 3 mm | 0.1181 in |
| 4 mm | 0.1575 in |
| 5 mm | 0.1969 in |
| 6 mm | 0.2362 in |
| 8 mm | 0.315 in |
| 10 mm | 0.3937 in |
| 12 mm | 0.4724 in |
| 15 mm | 0.5906 in |
| 20 mm | 0.7874 in |
| 25 mm | 0.9843 in |
| 25.4 mm | 1 in |
| 30 mm | 1.1811 in |
| 40 mm | 1.5748 in |
| 50 mm | 1.9685 in |
| 75 mm | 2.9528 in |
| 100 mm | 3.937 in |
What is a millimeter?
A millimeter is one thousandth of a meter. It is the standard unit on engineering drawings, for screw and drill sizes, rainfall totals and smartphone dimensions.
What is a inch?
The inch has been defined as exactly 2.54 centimeters since the 1959 international yard and pound agreement. Screens, tyres, pipes and US body measurements are still quoted in inches; 12 inches make a foot.
Frequently asked questions
How many inches are in one millimeter?
One millimeter equals 0.03937008 inches.
How do I convert millimeters to inches?
Use the formula in = mm ÷ 25.4. 5 ÷ 25.4 = 0.1969, so 5 millimeters = 0.1969 inches.
What is 100 mm in in?
100 mm = 3.937 in.
How do I convert inches back to millimeters?
Use the inverse formula mm = in × 25.4, or open the Inches to Millimeters converter.
More length conversions
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