PrintPixelA3 Size in Pixels
A3 is twice the area of A4 — 297 × 420 mm — and a common size for posters, menu boards and design portfolios. These are the pixel counts you need for a full-bleed A3 print.
A3 is 297 × 420 mm (29.7 × 42.0 cm, 11.69 × 16.54 in). At300 PPI, a full-bleed A3 needs 3508 × 4961 pixels — roughly 17 megapixels.
| Resolution | Pixels |
|---|---|
| 300 PPI | 3508 × 4961 px |
| 240 PPI | 2806 × 3969 px |
| 200 PPI | 2339 × 3307 px |
| 150 PPI | 1754 × 2480 px |
Pixel dimensions are computed from the physical size of A3 (297 × 420 mm) at each resolution.
A3 (297 × 420 mm) at common resolutions
| Resolution | Pixels | Physical size |
|---|---|---|
| 300 PPI | 3508 × 4961 px | 29.7 × 42.0 cm |
| 240 PPI | 2806 × 3969 px | 29.7 × 42.0 cm |
| 200 PPI | 2339 × 3307 px | 29.7 × 42.0 cm |
| 150 PPI | 1754 × 2480 px | 29.7 × 42.0 cm |
Pixel counts are computed from the real physical dimensions of A3 (297 × 420 mm) at each resolution — they are not hard-coded. To get these values for any other print size, use the calculator above.
Why the pixel count changes with PPI
A3's physical size is fixed — 297 × 420 mm — but the pixel count needed to fill it depends on the resolution.
PPI (pixels per inch) defines how many pixels map to one inch of print. A3 is 11.69 inches wide × 16.54 inches tall. At 300 PPI that's 3508 × 4961 pixels; at 150 PPI it's 1754 × 2480 — half the pixels, covering the same 297 × 420 mm of paper.
The values in the table above are computed from A3's real dimensions at each resolution, not hard-coded. For any other print size, use the calculator above.
A3 portrait vs landscape
In portrait orientation, A3 is 3508 × 4961 pixels at 300 PPI. Inlandscape it's 4961 × 3508 pixels — the same pixel count, just rotated. A3 is one of the most common landscape print sizes for posters and presentation boards.
A3's ISO 216 ratio of 1:1.414 stays the same in either orientation. The width is always 297 mm and the height is always 420 mm, whichever way you hold the sheet.
Can my image be printed on A3?
Compare your image's pixel dimensions to the values above. At least 3508 × 4961 pixels are needed to cover A3 at 300 PPI. If your image is smaller, it can still print — the effective PPI drops, and the result may look soft up close but fine from a distance.
The fastest check is tocheck your image with the Image Print Size Calculator. Upload a photo and it shows the exact resolution at A3, whether cropping is needed to fit A3's 1:1.414 aspect ratio, and a practical quality verdict. Images never leave your browser.
Practical details
A3 at 300 PPI needs 3508 × 4961 pixels, which is why professional poster printing usually starts from roughly a 16–17 MP image. At 240 PPI,2806 × 3969 pixels is high quality, and at 200 PPI,2339 × 3307 pixels is a very practical target for most A3 photo prints.
If your image is smaller than that, it can still be printed on A3 — it will simply look softer when inspected up close. Use the print quality checker to see whether the result suits your viewing distance.
A3 is a landscape-friendly size for posters, menus, signage and portfolios. Like A4 it keeps the ISO 216 ratio of 1:1.414, so a photo printed to fill an A3 sheet will usually need a crop on its longest edges to match the paper. For photos, an 8×10 or a custom size is often a better fit than A3.
A3 is double the area of A4 — see the A4 size in pixels page for the smaller step. The next size up is A2 size in pixels — double the area with the same aspect ratio. To judge whether your photo is sharp enough at A3, the print quality checker gives a verdict for this exact size, and the how large can I print my photo guide explains the reasoning behind it.