Millimeter to Inch Converter (mm to in)
1 millimeter = 0.0393701 inch. Millimeters measure small things such as screw sizes, camera sensors and rainfall, while inches dominate US hardware, pipe and tool sizes.
Result
8 mm = 0.31496063 in
How to convert millimeter to inch
Millimeters measure small things such as screw sizes, camera sensors and rainfall, while inches dominate US hardware, pipe and tool sizes. One inch is exactly 25.4 mm.
Formula
in = mm × 0.0393701
Worked example
8 mm × 0.0393701 = 0.314961 in
Millimeter to Inch quick-reference table
| Millimeter (mm) | Inch (in) |
|---|---|
| 1 mm | 0.0393701 in |
| 5 mm | 0.19685 in |
| 10 mm | 0.393701 in |
| 25 mm | 0.984252 in |
| 50 mm | 1.9685 in |
| 100 mm | 3.93701 in |
Real-life examples
An 8 mm bolt or drill bit is about 0.315 in (a little under 5/16 in), which helps when you only have inch-sized tools.
Frequently asked questions
How many mm is 1/4 inch?
1/4 in = 0.25 in = 6.35 mm.
Is 25 mm the same as 1 inch?
Almost. 25 mm is 0.984 in, so 1 inch is 25.4 mm. The 0.4 mm difference matters for precision parts.
What is 1 millimeter in inch?
1 millimeter = 0.0393701 inch (mm to in).
What is the formula to convert mm to in?
in = mm × 0.0393701. For example, 8 mm × 0.0393701 = 0.314961 in.
How do I convert in back to mm?
Use the reverse converter: 1 inch = 25.4 millimeter. Check: 0.314961 in converts back to 8 mm.
Reverse conversion
Need the other direction? Inch to Millimeter converter (in to mm): 1 inch = 25.4 millimeter.
Related length conversions
- Centimeter to Inch converter
- Inch to Centimeter converter
- Foot to Centimeter converter
- Centimeter to Foot converter
- Mile to Kilometer converter
- Kilometer to Mile converter