A4 size in pixels at 72, 96, 150 and 300 DPI
A4 paper is 210×297 mm (21×29.7 cm), or about 8.27×11.69 inches. To print it at 300 DPI you need 2480×3508 pixels.
If all you want is to get a few images onto A4 paper, you can skip the numbers: drop them into the A4 layout tool and it places them at real A4 size and exports at 300 DPI automatically.
A4 in pixels at common resolutions
| DPI | A4 portrait (width×height) | Typical use |
|---|---|---|
| 72 | 595×842 | PDF page units (1 point = 1/72 inch) |
| 96 | 794×1123 | CSS pixels on the web (1 px = 1/96 inch) |
| 150 | 1240×1754 | Drafts, prints where sharpness isn’t critical |
| 300 | 2480×3508 | Standard print quality |
| 600 | 4961×7016 | Very fine text and line art |
For landscape A4, swap the two numbers: at 300 DPI that’s 3508×2480 pixels.
How the numbers are worked out
DPI means dots per inch, and an inch is 25.4 mm, so:
pixels = millimetres ÷ 25.4 × DPI
At 300 DPI the width is 210 ÷ 25.4 × 300 ≈ 2480 and the height is 297 ÷ 25.4 × 300 ≈ 3508. The results are rounded to whole pixels, so different apps can disagree by one pixel. That makes no visible difference.
Too few pixels, or too many?
- Too few and the print looks soft. A 1080-pixel-wide phone screenshot stretched across the full 210 mm width of A4 works out at about 130 DPI: readable, but not as crisp as the original.
- Too many does no harm; the file is just bigger.
- An image’s “DPI” on its own tells you little. What matters is how large it’s printed. The same 2480-pixel-wide image is 300 DPI at 210 mm wide and 600 DPI at 105 mm wide.
Making an A4 canvas in an image editor
In Photoshop, GIMP and similar apps, pick the A4 preset when creating a new document, or enter 210×297 mm at a resolution of 300. If the app only accepts pixels, enter 2480×3508.
But if your goal is to print photos, screenshots or PDFs on A4 paper, building a canvas and positioning everything by hand is the long way round. Use the A4 printing tool instead: add your files, they’re laid out at real size, and nothing is uploaded.