Print files
A3 Print Size in Pixels at 300 DPI
A3 is 297×420 mm. At 300 DPI that is 3508×4961 pixels. It shares ISO ratio with A4, so you can scale an A3 crop down to A4 without a new composition — if you have the pixels.
Direct answer
A3 at 300 DPI is 3508×4961 pixels (portrait). Convert 297×420 mm: divide by 25.4, multiply by 300. Landscape is 4961×3508. A4 is the same ratio at 2480×3508. Do not stretch an 11×17 (3300×5100) or 11×14 file to A3. Export millimetres you actually sell.
UK and EU Etsy shops list A3 next to A4 the way US shops list 16×20 next to 8×10. Unlike 16×20 vs 8×10, A3 and A4 are the same shape. You can share a composition. You cannot share a 2480-pixel A4 file as a sharp A3.
Tabloid 11×17 is the US paper people confuse with A3. Close. Not the same. See 11×17.
- 1
Enter 297 × 420 mm
Not 11×17 in.
- 2
Crop around the subject
ISO height differs from 2:3 posters.
- 3
Confirm 3508×4961
Or the shop template’s exact pixels.
- 4
Save 300 DPI
JPG photos, PNG type.
ISO A ladder at 300 DPI
A5 1748×2480. A4 2480×3508. A3 3508×4961. A2 4961×7016. Same ratio. Scale down freely. Scale up only with more source pixels.
A5
A4 · 2480×3508 px
A3
| Size | Millimetres | Pixels |
|---|---|---|
| A4 | 210 × 297 | 2480 × 3508 |
| A3 | 297 × 420 | 3508 × 4961 |
| A2 | 420 × 594 | 4961 × 7016 |
A3 vs 11×17 vs 12×18
11×17 is 3300×5100 — taller than A3’s ratio. 12×18 is 2:3 (3600×5400). A3 is 1:√2. Three crops. If you ship to both the US and EU, export A3 and 12×18 separately from one focal point.
Export A3 from Reopic
Open Studio, add 297 × 420 mm. Export Artwork. Pair with 210 × 297 mm for A4 in the same session. Pro is $33 lifetime for batch.
Home A3 printers
Most home inkjets are A4. Buyers who order a digital A3 file need an A3 printer or a copy shop. Say so in the listing. “Fit to A4” will shrink their poster and generate a one-star review of your file.
FAQ: A3 print size pixels 300 DPI
How many pixels is A3 at 300 DPI?+
3508×4961 pixels in portrait.
Is A3 the same as 11x17?+
No. 11×17 is 3300×5100. A3 is 297×420 mm (3508×4961).
Can I enlarge A4 to A3?+
Only if the original still has A3 pixels. An A4-sized export (2480×3508) becomes 150 DPI at A3.
Is A3 twice A4?+
Twice the area, same ratio. Two A4 pages tile to A3.
