When 300 PPI is only a target
Effective PPI follows source pixels and printed size. It is a planning check, not a sharpness guarantee.
The placement changes the density
Effective PPI is the number of source pixels placed in one printed inch. A 3000 × 2400 pixel source placed at 10 × 8 inches has 300 pixels per inch in both directions. Place the same pixels at 20 × 16 inches and the density becomes 150 PPI. The source file has not changed.
The tool calculates density from the pixel dimensions entered. It does not inspect a file’s stored resolution tag. Changing a resolution label alone does not add pixels. Resampling changes pixel dimensions, but a larger count is not evidence that the original detail has been recovered.
| Source | Placement | Effective PPI |
|---|---|---|
| 3000 × 2400 px | 10 × 8 in | 300 |
| 3000 × 2400 px | 20 × 16 in | 150 |
Fill and fit can produce different readings
Fill must cover both canvas dimensions, so the smaller of source width ÷ canvas width and source height ÷ canvas height limits the placement. Fit keeps the whole source inside, so the larger ratio controls the placement.
A 3000 × 2000 source on a landscape 10 × 8 inch print gives 250 PPI in fill and 300 PPI in fit. Fill uses a physically larger image and crops the sides. Fit prints it at 10 × 6.667 inches with borders. The PPI figure needs the layout beside it.
3000 × 2000 px on 10 × 8 in: fill = 250 PPI with side crop; fit = 300 PPI at 10 × 6.667 in with borders.
Use the result as one check
The default 300 PPI is a planning reference for many close-viewed prints. The right target depends on the process, substrate, viewing distance and printer’s requirements. A large sign viewed across a room and a small photograph held in the hand have different conditions.
At or above target checks one numerical condition. It does not certify sharpness, focus, legal reuse or readiness for a particular print shop. Compression damage, motion blur, noise, color conversion and earlier upscaling are outside this tool. Printer DPI describes ink or toner dots and differs from source-image PPI.
If the print falls below target
The required-pixel field rounds the whole target canvas up to full pixels. In fit mode that canvas includes blank borders.
- Confirm the source dimensions and orientation first.
- Choose a smaller print, a different crop or a better original source when the result is below target.
- If you resample, inspect the result at its intended viewing conditions and request a proof when the result matters.
Sources
Calculations and examples above are provided by this site. The documentation below explains the underlying print concepts.