Convert dot per millimeter to pixel per inch instantly. Type in either field — results update live.
Selected dot/mm values converted to ppi using the exact factor from this tool.
| dot/mm | ppi |
|---|---|
| 0.01 | 0.254 |
| 0.1 | 2.54 |
| 1 | 25.4 |
| 2 | 50.7999999999 |
| 3 | 76.1999999999 |
| 5 | 126.9999999999 |
| 10 | 253.9999999997 |
| 20 | 507.9999999995 |
| 50 | 1,269.9999999986 |
| 100 | 2,539.9999999973 |
| 1,000 | 25,399.9999999726 |
Exact conversion factors in both directions, plus a worked example.
1 dot/mm = 25.4 ppi
1 ppi = 0.0393700787 dot/mm
To convert dot per millimeter to pixel per inch, multiply by 25.4.
To convert pixel per inch to dot per millimeter, multiply by 0.0393700787.
Example: convert 10 dot/mm to ppi
10 × 25.4 = 253.9999999997 ppi
Short background on the units used in this conversion.
Dot per millimeter equals 1,000 dot per meter — a compact metric resolution unit common in Europe and technical publishing.
Dot per millimeter converts easily to lines per millimeter in microfilm, PCB, and precision printing specifications.
Pixel per inch (PPI) counts screen or image pixels along one inch. Numerically it equals dot per inch here, but PPI refers to pixels in a digital image rather than physical ink dots.
PPI describes monitor density, retina displays, and export settings for web and mobile graphics where pixels — not ink — define resolution.
ppi = dot/mm × 25.4dot/mm = ppi × 0.03937007874, using the same exact factors as this converter.