Formula and method
print width in inches = pixel width ÷ PPI
PPI describes how many image pixels are placed in one inch of print. Printer DPI describes ink dots and is not the same measurement, although “DPI” is often used informally for both.
Assumptions and limits
- The image is not upscaled or cropped after calculation.
- Quality labels are general guidance; subject detail and viewing distance also matter.
- Printer margins and bleed are not subtracted.
Worked examples
3000 × 2400 pixels at 300 PPI
The print is exactly 10 × 8 inches, or 25.4 × 20.32 cm. This is a strong density for close-viewed photo prints.
6000 × 4000 pixels at 240 PPI
The result is 25 × 16.67 inches. At 240 PPI it is usually suitable for a detailed wall print.
Typical print density guidance
| Density | Typical use | Guidance |
|---|---|---|
| 300 PPI | Books and close-viewed photos | Excellent |
| 240 PPI | Quality photo and art prints | Very good |
| 150 PPI | Posters viewed farther away | Acceptable |
Frequently asked questions
Should I use DPI or PPI for image size?
Use PPI for pixels per printed inch. DPI is technically a printer’s ink-dot resolution.
Can I print larger than the calculated size?
Yes, but the effective PPI falls. Upscaling may help, but it cannot recreate all missing source detail.