At 300 dpi, use about 2480×3508 px for A4 and 3508×4961 px for A3. Posters viewed from farther away may work at 150–200 dpi. Enlarging cannot recreate missing detail.
Pixels and DPI describe different things
Pixels are the image’s individual samples. DPI describes how densely those samples are placed over a physical inch of print.
The same image looks sharper when printed smaller. Detailed photographs and fine type often target 300 dpi; distant posters may need less.
Common paper-size targets
At 300 dpi, A5 is roughly 1748×2480 px, A4 is 2480×3508 px and A3 is 3508×4961 px. Swap width and height for landscape.
Professional printing may require bleed beyond the trimmed edge, so use the printer’s template when provided.
- A5: 1748×2480 px
- A4: 2480×3508 px
- A3: 3508×4961 px
Why enlargement has limits
Adding pixels through resizing does not restore detail absent from the source. It can soften edges and text.
Find the original photo or design file instead of enlarging an image saved from social media.
Make a physical test
Print a representative crop at actual size using the intended printer and paper. Inspect faces, small text and QR codes from the normal viewing distance.
Before resizing
- ✓Chosen paper size and orientation
- ✓Chosen a sensible DPI
- ✓Started with the largest source
- ✓Kept aspect ratio
- ✓Test-printed important details
Image Resizer
Resize by pixels or choose A3, A4 and A5 proportions directly.
Image Resizer→This article gives general guidance. If a recipient, printer or official service provides its own requirements, follow those requirements first.
A SMALL NOTE FROM SPACEMaking Jupiter larger on a screen does not invent new storms. A good source image is the telescope that reveals detail.