Print size is not fixed by the file alone. The same pixel dimensions can produce a small, detailed print or a larger print intended to be viewed from farther away.
Calculate print size from pixels
Calculate width and height independently. If a 3600 × 2400 image is printed at 300 PPI, the result is 12 × 8 inches. At 150 PPI, it becomes 24 × 16 inches.
| Target PPI | Print size | Typical context |
|---|---|---|
| 300 | 12 × 8 in | Close-viewed photo print |
| 240 | 15 × 10 in | Detailed general print |
| 150 | 24 × 16 in | Larger print viewed farther away |
| 100 | 36 × 24 in | Poster-style distance viewing |
Choose a useful target PPI
300 PPI is a common planning target for photographs viewed at arm's length. It is not a universal pass/fail line. Large posters can work at lower effective PPI because viewers stand farther away, while fine line art or small text may benefit from a higher-resolution source.
Fit, crop, and aspect ratio
A file and paper size may use different aspect ratios. A 3:2 camera photo does not fill an 8 × 10 print without cropping or borders. Calculate the effective PPI after choosing the final crop, because removing pixels reduces the resolution available for printing.
Before sending a file to print
- Use the original image rather than a messaging-app copy.
- Choose final physical dimensions and crop.
- Calculate effective PPI on both axes.
- Inspect focus and compression at 100% zoom.
- Confirm the print provider's color and file-format requirements.