MM to Inches Converter
Turn millimeters into inches, shown as a decimal and broken down into feet and inches.
Convert millimeters to inches
Type a length and the equivalent in inches updates as you go.
Decimals are fine, try 25.4 for exactly one inch.
Common conversions
| Millimeters (mm) | Inches |
|---|---|
| 1 | 0.03937007874 |
| 10 | 0.3937007874 |
| 25.4 | 1 |
| 50 | 1.968503937 |
| 100 | 3.937007874 |
| 254 | 10 |
| 1000 | 39.37007874 |
1 in is 25.4 mm, so 1 mm = 0.03937007874 in.
Frequently Asked Questions
One millimeter is 0.03937007874 inches. So 10 mm is 0.3937007874 inches and 100 mm is 3.937007874 inches.
Multiply the number of millimeters by 0.03937007874. So 50 mm becomes 50 × 0.03937007874 = 1.968503937 inches.
Because that is the international agreement: since 1959 an inch has been defined as exactly 25.4 millimeters, and both units derive from the same standard. It is an exact definition rather than a measured approximation, which is why this converter gives you exactly 1 inch for 25.4 mm.
Yes, decimals are expected. Enter 25.4 for exactly one inch, or 6.35 for a quarter inch. Results are shown to the full precision of the conversion itself, then rounded to the few digits your measurement is actually good to.
No. The conversion runs in your browser as you type. Your input is never uploaded or stored.