How it works
Effective PPI = image pixels ÷ printed size in inches. We rotate the print size to match your image and report two numbers: when the image fills the print (edges cropped if the shape differs) and when it fits inside (margins left).
The DPI stored in JPEG (JFIF/EXIF) or PNG (pHYs) is shown as a fact, because some software uses it as a default print size — but it never changes the verdict.
FAQ
- My photo says 72 DPI. Is that bad for printing?
- Not by itself. A 72 DPI tag only sets a default size in some programs. A 4000 × 3000 pixel photo is 300 PPI at 13.3 × 10 inches whatever its DPI tag says.
- What PPI do I need?
- About 300 PPI for photos and flyers viewed up close, around 150 PPI for posters seen from a distance. Check your printer's requirement.
- Can I increase the DPI?
- Changing the DPI tag does not add detail. Only a larger original (more pixels) or printing smaller improves effective PPI.