Print Size and Resolution Calculator
Notes on Resolution:
Keep in mind the resolution of 300 dpi is given for a small print around the size of A4 with its related viewing distance. If you print posters you’ll most likely not see it as close as a magazine and 150 dpi can probably be just fine.
Also, with the Ai tools developing very fast, these resolutions calculator could very well be a thing of the past in the near future.
Do you want more calculators?
Here is a link to a list of photo calculators.