This millimeters to inches converter gives you the mm to in result instantly, in your browser, with the exact ratio so you can verify it. 1 millimeter is about 0.0393701 inches, and going the other way, 1 inch is 25.4 millimeters. Millimeters are part of the metric system used in most countries; inches are an imperial unit still common in the United States and the United Kingdom.
To convert by hand, multiply the number of millimeters by 0.0393701. For example, 10 millimeters is 0.393701 inches and 100 millimeters is 3.93701 inches. The table below lists the most requested values, and the converter above accepts decimals for anything in between.
mm to in formula
in = mm × 0.0393701
1 millimeter is about 0.0393701 inches. Multiply the value in millimeters by that factor to get inches.
Millimeters to Inches conversion table
| millimeters | inches | Rounded |
|---|---|---|
| 1 mm | 0.0393701 in | 0.0394 |
| 2 mm | 0.0787402 in | 0.0787 |
| 3 mm | 0.11811 in | 0.118 |
| 4 mm | 0.15748 in | 0.157 |
| 5 mm | 0.19685 in | 0.197 |
| 6 mm | 0.23622 in | 0.236 |
| 7 mm | 0.275591 in | 0.276 |
| 8 mm | 0.314961 in | 0.315 |
| 9 mm | 0.354331 in | 0.354 |
| 10 mm | 0.393701 in | 0.394 |
| 12 mm | 0.472441 in | 0.472 |
| 15 mm | 0.590551 in | 0.591 |
| 20 mm | 0.787402 in | 0.787 |
| 25 mm | 0.984252 in | 0.984 |
| 30 mm | 1.1811 in | 1.18 |
| 40 mm | 1.5748 in | 1.57 |
| 50 mm | 1.9685 in | 1.97 |
| 60 mm | 2.3622 in | 2.36 |
| 70 mm | 2.75591 in | 2.76 |
| 75 mm | 2.95276 in | 2.95 |
| 80 mm | 3.14961 in | 3.15 |
| 90 mm | 3.54331 in | 3.54 |
| 100 mm | 3.93701 in | 3.94 |
| 150 mm | 5.90551 in | 5.91 |
| 200 mm | 7.87402 in | 7.87 |
| 250 mm | 9.84252 in | 9.84 |
| 300 mm | 11.811 in | 11.8 |
| 500 mm | 19.685 in | 19.7 |
| 750 mm | 29.5276 in | 29.5 |
| 1,000 mm | 39.3701 in | 39.4 |
Frequently asked questions
How many inches are in 5 millimeters?
5 mm = 0.19685 in. Multiply 5 by 0.0393701, the number of inches in one millimeter. The converter on this page does the same arithmetic for any value, including decimals.
What is the formula to convert millimeters to inches?
in = mm × 0.0393701. The factor comes from the definitions of the units: 1 millimeter is about 0.0393701 inches. Worked example: 12 mm = 0.472441 in.
Is 30 mm the same as 1.1811 in?
Yes. 30 mm = 1.1811 in. Rounded to four decimals it is 1.181 in.
How do I convert inches back to millimeters?
Divide by 0.0393701, or multiply by 25.4: 1 inch is 25.4 millimeters. The inches to millimeters page linked above lists common values the other way.
Is the mm to in conversion exact?
1 millimeter is about 0.0393701 inches. The ratio is a defined constant but produces a long decimal, so this page rounds to six significant digits, which is more precision than any everyday measurement needs.