A4 Resolution Calculator
Find the exact pixel dimensions needed to print A4 (210 x 297 mm, ISO 216) at 72, 150 and 300 DPI, in portrait and landscape.
Pixels needed
Portrait (210 x 297 mm): 2480 x 3508 px
Landscape (297 x 210 mm): 3508 x 2480 px
Paper dimensions are ISO 216. Pixel counts are rounded to whole pixels. Allow a small bleed margin if your printer requires it.
| DPI | Portrait pixels |
|---|---|
| 72 | 595 x 842 |
| 150 | 1240 x 1754 |
| 300 | 2480 x 3508 |
| 600 | 4961 x 7016 |
How to use this calculator
1. Pick a DPI. 2. Read the exact pixels needed for the paper size in portrait and landscape. 3. Compare with your image dimensions.
Formula
Pixels = (Millimeters / 25.4) x DPI. A4 is 210 x 297 mm, A3 is 297 x 420 mm, A5 is 148 x 210 mm (ISO 216).
Paper sizes and viewing distance
| Size | Millimeters | Pixels at 300 DPI |
|---|---|---|
| A5 | 148 x 210 mm | 1748 x 2480 px |
| A4 | 210 x 297 mm | 2480 x 3508 px |
| A3 | 297 x 420 mm | 3508 x 4961 px |
| Viewing situation | Target DPI | Why |
|---|---|---|
| Close-up photo | 300 | Held in the hand; fine detail is visible. |
| Wall poster | 150 | Viewed from a few feet away; finer detail cannot be resolved. |
| Billboard | 72 | Viewed from far away; 300 DPI would be wasted pixels. |
Frequently asked questions
How many pixels do I need for A4 at 300 DPI?
At 300 DPI, A4 needs 2480 x 3508 pixels in portrait orientation.