How to convert dots per millimeter to dots per inch
dpi = dot/mm × 25.4Multiply the value in dots per millimeter by 25.4. To go the other way, multiply by 0.03937007874 (or divide by 25.4).
A dot per millimeter is larger than a dot per inch: one dot per millimeter contains 25.4 dots per inch.
Worked examples
- 1 dot per millimeter1 dot/mm × 25.4 = 25.4 dpi
- 5 dots per millimeter5 dot/mm × 25.4 = 127 dpi
- 10 dots per millimeter10 dot/mm × 25.4 = 254 dpi
- 20 dots per millimeter20 dot/mm × 25.4 = 508 dpi
- 100 dots per millimeter100 dot/mm × 25.4 = 2,540 dpi
Dots per millimeter to dots per inch conversion table
Values are calculated by the conversion engine and rounded to 8 significant figures.
| Dots per millimeter (dot/mm) | Dots per inch (dpi) |
|---|---|
| 0.1 dot/mm | 2.54 dpi |
| 0.25 dot/mm | 6.35 dpi |
| 0.5 dot/mm | 12.7 dpi |
| 1 dot/mm | 25.4 dpi |
| 2 dot/mm | 50.8 dpi |
| 3 dot/mm | 76.2 dpi |
| 4 dot/mm | 101.6 dpi |
| 5 dot/mm | 127 dpi |
| 6 dot/mm | 152.4 dpi |
| 7 dot/mm | 177.8 dpi |
| 8 dot/mm | 203.2 dpi |
| 9 dot/mm | 228.6 dpi |
| 10 dot/mm | 254 dpi |
| Dots per millimeter (dot/mm) | Dots per inch (dpi) |
|---|---|
| 12 dot/mm | 304.8 dpi |
| 15 dot/mm | 381 dpi |
| 20 dot/mm | 508 dpi |
| 25 dot/mm | 635 dpi |
| 30 dot/mm | 762 dpi |
| 40 dot/mm | 1,016 dpi |
| 50 dot/mm | 1,270 dpi |
| 75 dot/mm | 1,905 dpi |
| 100 dot/mm | 2,540 dpi |
| 250 dot/mm | 6,350 dpi |
| 500 dot/mm | 12,700 dpi |
| 1,000 dot/mm | 25,400 dpi |
About the units
Dot per millimeter (dot/mm)
The dot per millimeter (dot/mm) is a unit of digital image resolution in the metric system. One dot per millimeter equals 1,000 dots per meter (dot/m).
Dot per inch (dpi)
Dots (or pixels) per inch; 300 dpi is the usual target for high-quality print. One dot per inch equals 39.37007874 dots per meter (dot/m).
Frequently asked questions
How many dots per inch are in one dot per millimeter?
There are 25.4 dots per inch in one dot per millimeter, and this value is exact by definition.
How do I convert dots per millimeter to dots per inch?
Multiply the number of dots per millimeter by 25.4. For example, 10 dot/mm × 25.4 = 254 dpi.
How many dots per millimeter are in one dot per inch?
One dot per inch equals 0.03937007874 dots per millimeter. That is the reverse factor, 1 ÷ 25.4.
What is 10 dots per millimeter in dots per inch?
10 dot/mm = 254 dpi.
Is this dot/mm to dpi converter accurate?
Yes. Both units are defined exactly in terms of SI units, so the conversion factor is exact; results are shown to 12 significant figures by default and you can change precision in the converter. Calculations run in your browser using the same tested engine that generated this page.