Inches to Millimeters Converter
1 inch = 25.4 millimeters
Type a value in either box: the conversion between inches (in) and millimeters (mm) updates instantly.
Millimeters to Inches Converter
Good to know
Common fractional sizes: 1/8 in = 3.175 mm, 1/4 in = 6.35 mm, 1/2 in = 12.7 mm and 3/4 in = 19.05 mm.
How to convert inches to millimeters
To convert inches to millimeters, multiply the number of inches by 25.4. To go the other way, multiply millimeters by 0.03937008.
mm = in × 25.4
Worked examples
- 0.25 in = 6.35 mm
- 0.5 in = 12.7 mm
- 1 in = 25.4 mm
- 6 in = 152.4 mm
Inches to Millimeters conversion table
| Inches (in) | Millimeters (mm) |
|---|---|
| 0.0625 in | 1.5875 mm |
| 0.125 in | 3.175 mm |
| 0.25 in | 6.35 mm |
| 0.375 in | 9.525 mm |
| 0.5 in | 12.7 mm |
| 0.625 in | 15.875 mm |
| 0.75 in | 19.05 mm |
| 0.875 in | 22.225 mm |
| 1 in | 25.4 mm |
| 1.5 in | 38.1 mm |
| 2 in | 50.8 mm |
| 3 in | 76.2 mm |
| 4 in | 101.6 mm |
| 5 in | 127 mm |
| 6 in | 152.4 mm |
| 10 in | 254 mm |
| 12 in | 304.8 mm |
About the units
Inches (in)
The inch (in) is defined as exactly 2.54 centimeters. It is used in the US and UK for height, screen sizes, tools and construction.
Millimeters (mm)
The millimeter (mm) is one thousandth of a meter. It is used for precise measurements in engineering, hardware and rainfall.
Frequently asked questions
How do I convert inches to millimeters?
mm = in × 25.4What is 0.5 in in millimeters?
How many millimeters are in an inch?
How many inches are in a millimeter?
Conversion factors use exact international definitions where they exist (for example 1 inch = 2.54 cm and 1 lb = 0.45359237 kg). Results are rounded for display only.