A3 at 72 DPI is 842 × 1191 pixels
A3 (297 × 420 mm) at 72 DPI is 842 × 1191 pixels, which is 1 megapixels.
| Portrait | 842 × 1191 pixels |
|---|---|
| Landscape | 1191 × 842 pixels |
| With 3 mm bleed | 859 × 1208 pixels |
| Megapixels | 1 |
| Aspect ratio | 1.41:1 (1 to √2 before rounding) |
| File size | 2.9 MB as uncompressed 8-bit RGB; a JPEG or PNG is smaller |
| Paper size | 297 × 420 mm (11.69 × 16.54 in) |
The working
Pixels are inches multiplied by the resolution, and an inch is 25.4 mm.
- Width: 297 mm ÷ 25.4 = 11.693 in; 11.693 in × 72 = 841.9, which rounds to 842 pixels.
- Height: 420 mm ÷ 25.4 = 16.535 in; 16.535 in × 72 = 1,190.6, which rounds to 1191 pixels.
Bleed is extra image past the trim line, so that a cut that lands slightly off still leaves ink to the edge. Print shops usually ask for 3 mm on every side of an A-series page, which makes the file 859 × 1208 pixels.
Is your photo big enough?
To fill A3 at 72 DPI an image needs at least 842 × 1191 pixels. Cropped to fill the sheet:
- A 12 megapixel phone photo (4000 × 3000) gives 242 DPI: enough.
- A 24 megapixel camera photo (6000 × 4000) gives 342 DPI: enough.
- A 48 megapixel photo (8000 × 6000) gives 484 DPI: enough.
At 72 DPI the pixels of a print blend together from about 47.7 inches (121 cm) away. 72 DPI is the old screen convention: early Macintosh displays showed 72 pixels to the inch, matching the 72 points in an inch of type. Many image files still carry a 72 DPI tag for that reason.
A3 at other resolutions
| Resolution | Pixels | With bleed | Megapixels | Uncompressed |
|---|---|---|---|---|
| 72 DPI | 842 × 1191 | 859 × 1208 | 1 | 2.9 MB |
| 96 DPI | 1123 × 1587 | 1145 × 1610 | 1.8 | 5.1 MB |
| 100 DPI | 1169 × 1654 | 1193 × 1677 | 1.9 | 5.5 MB |
| 150 DPI | 1754 × 2480 | 1789 × 2516 | 4.3 | 12 MB |
| 200 DPI | 2339 × 3307 | 2386 × 3354 | 7.7 | 22 MB |
| 240 DPI | 2806 × 3969 | 2863 × 4025 | 11 | 32 MB |
| 300 DPI | 3508 × 4961 | 3579 × 5031 | 17 | 50 MB |
| 400 DPI | 4677 × 6614 | 4772 × 6709 | 31 | 89 MB |
| 600 DPI | 7016 × 9921 | 7157 × 10063 | 70 | 199 MB |
| 1200 DPI | 14031 × 19843 | 14315 × 20126 | 278 | 797 MB |
Other sizes at 72 DPI
- A0
- A1
- A2
- A4
- A5
- A6
- A7
- Letter
- Legal
- Tabloid
- Half Letter
- 4 × 6 in
- 5 × 7 in
- 8 × 10 in
- 11 × 14 in
- 16 × 20 in
- 12 × 12 in
- 12 × 18 in
- 18 × 24 in
- 24 × 36 in
- Business card
A3 is two A4 pages side by side, used for small posters, drawings and spreads. See A3 in pixels at every resolution or everything at 72 DPI.