What resolution does a poster need?
A print looks sharp when there are enough pixels for every inch of paper. That is DPI, dots per inch. Here is how much you need, without the jargon.
Upload it and see the quality for every size.
Check your fileThe quick rule
- •300 DPI: perfect, even up close.
- •200 DPI: looks sharp at arm’s length.
- •150 DPI: fine for big posters seen from a step back.
- •Under 100 DPI: likely to look soft or blocky.
Work it out
DPI = pixels ÷ inches. A photo 4000 pixels tall printed as an A3 (16.5 inches tall) gives about 242 DPI: sharp. The same photo as an A1 (33.1 inches) gives about 121 DPI: fine from across a room, soft close up.
Bigger posters need fewer DPI
People stand further from a big poster, so it needs fewer dots per inch to look just as sharp. That is why an A1 at 150 DPI on a wall looks as good as an A4 at 300 DPI on a desk.
Enlarging does not add detail
Making an image bigger in an editor adds pixels but no detail. Always start from the largest original you have; photos sent through messaging apps are usually shrunk.
We check it for you
Upload your file and we tell you straight away whether it is sharp enough for the size you chose.
Questions
Is 72 DPI OK for printing?
No. 72 DPI is a screen setting; what matters is the pixel count. Divide the pixels by the print size in inches to see the real DPI.
Can I print a phone photo as a poster?
Yes. A 12 megapixel phone photo prints sharply up to A3 and looks good at A2.
Upload it and see the quality for every size.
Check your fileRelated guides
- A paper sizes: A1 to A5A1, A2, A3, A4 and A5 in mm, cm and inches, how they relate, and the pixel size you need to print each one sharply.
- Print photos from your phonePrint photos straight from your iPhone or Android in frame sizes up to A1: how big a phone photo prints, the best sizes, and fixing HEIC photos.
- How to turn a photo into a posterTurn a photo into a poster in three steps: choose a size for your wall or frame, crop it to fit, and check it will print sharply.