in → mm
Inches to Millimeters Converter
1 inch (in) is equal to 25.4 millimeters (mm). To convert inches to millimeters, multiply the inch value by 25.4.
Inches to millimeters converts US hardware, tools and screen specs into precise metric values. One inch is exactly 25.4 millimeters — a half-inch pipe is 12.7 mm, and a quarter-inch drill bit is 6.35 mm.
How to convert inches to millimeters
millimeters = inches × 25.4
Inches to Millimeters conversion table
| inches (in) | millimeters (mm) |
|---|---|
| 0.125 | 3.17 |
| 0.25 | 6.35 |
| 0.5 | 12.7 |
| 0.75 | 19.05 |
| 1 | 25.4 |
| 1.5 | 38.1 |
| 2 | 50.8 |
| 3 | 76.2 |
| 4 | 101.6 |
| 6 | 152.4 |
| 12 | 304.8 |
| 36 | 914.4 |
Frequently asked questions
How many millimeters are in a inch?
There are 25.4 millimeters in 1 inch. Multiply any inch value by 25.4 to get the equivalent in millimeters.
What is 1 in in millimeters?
1 in equals 25.4 mm. You can verify this with the interactive converter above — the result updates instantly as you type.
What is the formula to convert inches to millimeters?
millimeters = inches × 25.4. For example, 4 in × 25.4 = 101.6 mm.
Can I measure something in inches without a tape measure?
Yes — Scale for Grams' Size mode estimates an object's height, width and depth in centimeters from a single photo using computer vision. It works free in the browser at scaleforgrams.com with no account required.
Scale for Grams
Don't know the inch value? Weigh it with a photo.
Scale for Grams estimates any object's weight from a single photo and shows it in grams, kilograms, pounds and ounces at once — free, in your browser.
Try the photo scale