Free tool
Poster DPI & Resolution Calculator
Enter your image dimensions to estimate print DPI at A5, A4, A3, A2 or A1, or calculate the pixels needed for a chosen poster size.
300 DPI is not always required for larger posters because they are normally viewed from further away.
What DPI will my image print at?
How many pixels do I need?
4,961 × 7,016 px
To print A2 (420 × 594 mm) at 300 DPI, your image needs to be at least 4,961 × 7,016 pixels. Portrait or landscape either way round is fine.
DPI, pixels and poster sizes - the short version
Pixels are the dots that make up your image file - a 3000 × 2000 px image has six million of them. DPI (dots per inch) describes how tightly those pixels are packed when printed: the same image is high DPI printed small and lower DPI printed large.
Larger posters need more pixels for the same DPI, but they also hang on a wall and are viewed from further away - so they can use a lower DPI and still look sharp. As a rough guide: aim for 200+ DPI on hand-held sizes like A5, around 150 DPI for A3/A2, and around 110 DPI for A1. These match the size-aware thresholds our poster editor uses.
DPI is not the whole story: a sharp, well-lit original prints better than a blurry or heavily compressed one at any DPI. Start with the highest-quality file you have - the original from your camera or AI tool, not a screenshot or chat preview.
FAQ
What DPI do I need for an A3 poster?
A3 is 297 × 420 mm (11.7 × 16.5 in). At the 300 DPI reference that is about 3508 × 4961 px, but A3 posters are usually viewed from arm's length or further, so around 150 DPI (roughly 1750 × 2480 px) generally prints well. Use the calculator above for your exact image.
How many pixels do I need for A1?
A1 is 594 × 841 mm (23.4 × 33.1 in). At 300 DPI that would be 7016 × 9933 px - more than most cameras produce. Because A1 hangs on a wall and is viewed from a distance, around 110 DPI (about 2570 × 3640 px) still prints sharply.
Is 150 DPI enough for a poster?
For larger posters, yes in most cases. 150 DPI at A3 or A2 looks sharp at normal viewing distances. For small hand-held prints like A5, aim higher - closer to 200 DPI or more.
Is 300 DPI necessary for large posters?
No. 300 DPI is the professional reference for items held up close. Larger posters are viewed from further away, so they print sharply at much lower DPI. Our thresholds account for this per size - the same ones used in our poster editor.
What is the difference between pixels and DPI?
Pixels are the fixed number of dots in your image file. DPI (dots per inch) describes how densely those pixels are spread when printed at a given size. The same image has a high DPI printed small and a lower DPI printed large - the file itself does not change.