Answer “what resolution do I need?” with: finished width in inches × target DPI. 300 DPI for close viewing; often less for posters.
How print size is calculated
Print width (inches) = pixels ÷ DPI. Centimeters = inches × 2.54. For example, a 3000×2000 px image at 300 DPI prints at about 25.4 × 16.93 cm.
What DPI should you use?
300 DPI is the usual target for photo-quality prints viewed up close. 150–200 DPI often works for posters. Large-format and outdoor prints can go much lower because viewing distance is greater.
Pixels vs. DPI metadata
Changing the DPI tag in software does not add detail. Only the pixel count and the physical print size determine effective resolution. Use a calculator with real pixel dimensions.
Print size by DPI
| DPI | Print size (cm) | Print size (in) | Quality |
|---|---|---|---|
| 72 | 105.83 × 70.56 cm | 41.67 × 27.78 in | Low print resolution |
| 100 | 76.2 × 50.8 cm | 30 × 20 in | Suitable for viewing from a distance |
| 150 | 50.8 × 33.87 cm | 20 × 13.33 in | Good for larger prints |
| 200 | 38.1 × 25.4 cm | 15 × 10 in | Good for larger prints |
| 240 | 31.75 × 21.17 cm | 12.5 × 8.33 in | Very good print quality |
| 300 | 25.4 × 16.93 cm | 10 × 6.67 in | Excellent print quality |
| 600 | 12.7 × 8.47 cm | 5 × 3.33 in | Excellent print quality |
FAQ
How big can I print my photo?
Divide each pixel dimension by your target DPI. At 300 DPI, 3000×2000 px prints about 25.4 × 16.93 cm. At 150 DPI the same file prints about 50.8 × 33.87 cm.
Is PPI the same as DPI for printing?
For planning print size, people often use DPI and PPI interchangeably to mean pixels per inch. Printers still use dots of ink; your planning number is pixels ÷ print inches.