1 inch (in) = 25.4 millimeters (mm). To convert, multiply by 25.4: mm = in × 25.4. For example, 5 in = 127 mm.
mm = in × 25.4
Inches to millimeters table
| Inches (in) | Millimeters (mm) |
|---|---|
| 1 | 25.4 |
| 2 | 50.8 |
| 3 | 76.2 |
| 4 | 101.6 |
| 5 | 127 |
| 10 | 254 |
| 20 | 508 |
| 25 | 635 |
| 50 | 1,270 |
| 100 | 2,540 |
| 250 | 6,350 |
| 500 | 12,700 |
| 1,000 | 25,400 |
The two units
Inch (in). Exactly 25.4 millimeters, by the 1959 international definition.
Millimeter (mm). One thousandth of a meter.
Because both units are defined in terms of the same base unit, the factor 25.4 is exact, not a rounded measurement.
Convert inches to other units
- Inches to meters — 1 in = 0.0254 m
- Inches to kilometers — 1 in = 0.0000254 km
- Inches to centimeters — 1 in = 2.54 cm
- Inches to micrometers — 1 in = 25,400 µm
- Inches to nanometers — 1 in = 25,400,000 nm
- Inches to miles — 1 in = 0.0000157828 mi
- Inches to yards — 1 in = 0.0277777778 yd
- Inches to feet — 1 in = 0.0833333333 ft
- Inches to nautical miles — 1 in = 0.0000137149 nmi
Convert other units to millimeters
Questions people ask
- How many millimeters are in a inch?
- 25.4, exactly.
- How do you convert inches to millimeters?
- mm = in × 25.4. It is the same as dividing by 0.0393700787.
- How do you convert millimeters back to inches?
- in = mm ÷ 25.4. See millimeters to inches.
Results use the legal definitions of each unit and are checked against the Pint unit library. Display rounds to 10 significant digits. All unit conversions · More tools
Legal entity
Devansh Yadav
Moradabad, Uttar Pradesh
Governing law: Courts at Moradabad, Uttar Pradesh
Phone: +91 8433475698
Legal: legal@analyzeit.in