Photo Print Size Calculator
Check whether an image has enough resolution for a chosen print size and how it will look.
Last updated · View algorithm, constants and default inputs (JSON)
About this calculator
PPI can help compare image and print dimensions, but 300, 240 and 150 PPI are reference bands rather than guarantees of sharpness. Viewing distance, printer, paper and image content also matter.
Worked example
calculated with the default values below
Image width 6,000 px · Image height 4,000 px · Print width 16 in · Print height 12 in · Crop to a standard aspect Keep the original ratio Resulting print resolution 333.3 ppi · Image megapixels 24.0 MP · Print quality Excellent — full photo quality · Pixels needed for 300 ppi at this size 4800 × 3600 px · Crop note Keeping the original aspect ratio, so no pixels are lost · Largest print at 300 ppi 20.0 in
General background references
Disclaimer
These calculators give general estimates. Sizing, pricing, availability and standards vary by brand, retailer and country, so treat the output as a starting point and confirm it against the seller's or authority's own figures.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
PPI = min(Wpx ÷ W_in, Hpx ÷ H_in); MP = Wpx × Hpx ÷ 10^6
- PPI
- Pixels per inch
- Wpx
- Image width (px)
- Hpx
- Image height (px)
- W_in
- Print width (in)
- MP
- Megapixels
Max print at 300 PPI = Wpx ÷ 300 in; quality tiers at 150/200/240/300 PPI.
Frequently asked questions
How does print size change effective PPI?
The tool divides image width by print width and image height by print height, then uses the lower value. A 6,000 × 4,000 image at 16 × 12 inches gives 333 PPI; at 20 × 13 inches it gives 300 PPI, still in its Excellent band. It does not crop pixels for this calculation even if aspect ratios differ.