Inches to millimeters
For screws, pipes, bolts and printing, where inch sizes meet metric parts. One inch is exactly 25.4 mm.
1 inch = 25.4 millimeters
Formula: millimeters = inches × 25.4
How to convert
How to convert inches to millimeters
One inch is 25.4 millimeters. To convert, use this formula:
millimeters = inches × 25.4
Example: 1.25 inches = 31.75 millimeters.
Inches to millimeters table
| inches (in) | millimeters (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 |
| 1 in | 25.4 mm |
| 1.25 in | 31.75 mm |
| 1.5 in | 38.1 mm |
| 2 in | 50.8 mm |
| 3 in | 76.2 mm |
| 4 in | 101.6 mm |
| 6 in | 152.4 mm |
| 12 in | 304.8 mm |
About the units
- An inch is an imperial and US unit defined since 1959 as exactly 2.54 centimeters.
- A millimeter is one thousandth of a meter, the thickness of a credit card is just under one.
Related
More length conversions
- Centimeters to inchesUseful for clothing sizes, screen sizes, paper and anything measured with a metric ruler that you know in inches.
- Inches to centimetersHandy for screen and TV sizes, heights, waist sizes and product dimensions listed in inches.
- Millimeters to inchesCommon for tools, drill bits, screws, jewelry and technical drawings that mix metric and imperial sizes.
- Feet to metersUsed for heights, room sizes, building plans and altitudes quoted in feet.
- Meters to feetUseful for converting heights, swimming pools, room dimensions and distances in metric countries.
- Kilometers to milesFor running distances such as 5K and 10K races, road trips and speed limits abroad.
- Miles to kilometersFor road signs, car mileage, flight distances and running plans written in miles.
- Centimeters to feetMostly for heights: 180 cm is about 5.9 feet, or 5 feet 11 inches.
- Feet to centimetersFor heights and short lengths given in feet. One foot is exactly 30.48 cm.
- Yards to metersFor sports fields, golf distances and fabric. A yard is exactly 0.9144 meters.
- Meters to yardsFor running and swimming distances, and fabric sold by the meter when you think in yards.
Frequently asked questions
How many millimeters are in a inch?
One inch equals 25.4 millimeters.
How do I convert inches to millimeters?
Use the formula millimeters = inches × 25.4. For example, 1.25 inches is 31.75 millimeters.
What is 1.25 inches in millimeters?
1.25 inches is 31.75 millimeters.
How do I convert millimeters back to inches?
Use the formula inches = millimeters ÷ 25.4. One millimeter is 0.03937007874 inches.