AI & digital · Reference
Your 1024-pixel image prints at 8.7 centimetres.
The most common disappointment with generated art is discovering, at the print shop, how small it actually is. The arithmetic is simple and worth doing before you pay.
Arithmetic, not opinion. The numbers on this page are calculated, and the working is shown so you can check it yourself.
A printed image needs enough pixels per unit of paper. The standard for photographic quality is 300 pixels per inch. Below roughly 150 ppi, the softness is visible at normal viewing distance.
So the size a file can print is simply its pixel count divided by the ppi you want:
printable inches = pixels ÷ ppi
A 1024 × 1024 output — the default for a great many image models — divided by 300 gives 3.41 inches, or 8.7 centimetres square. Smaller than a coaster. At a more forgiving 150 ppi it stretches to 17.3 cm, about the size of a postcard.
| Print size | At 300 ppi | At 150 ppi |
|---|---|---|
| A4 — 21 × 29.7 cm | 2480 × 3508 | 1240 × 1754 |
| A3 — 29.7 × 42 cm | 3508 × 4961 | 1754 × 2480 |
| A2 — 42 × 59.4 cm | 4961 × 7016 | 2480 × 3508 |
| A1 — 59.4 × 84.1 cm | 7016 × 9933 | 3508 × 4961 |
| 50 × 70 cm | 5906 × 8268 | 2953 × 4134 |
Set that against what generators typically hand you — commonly between 1024 and 2048 pixels on the long edge — and the gap is stark. A 2048-pixel image is about 17 cm at 300 ppi. Even A4 needs 3508 pixels tall.
What to do about it
Generate larger if the tool lets you. Always the best answer, because the detail is real rather than invented. Many tools offer a high-resolution or 2K/4K output, sometimes only on paid tiers.
Upscale second. Modern AI upscalers are genuinely good and will get a 1024-pixel image to a convincing A3. They are inventing detail rather than recovering it, which matters more in some images than others: foliage, fabric and texture upscale convincingly, while faces, text and fine straight lines are where invented detail becomes obvious.
Accept 150 ppi for large work. The 300 ppi standard assumes you will hold the print at reading distance. A big piece on a wall is viewed from two metres, and 150 ppi — or even less — is genuinely fine there. This is why billboards print at single-digit ppi and still look sharp from the road.
Print small and frame big. A modest print with a deep mat often looks more considered than a large soft one, and it costs less.
Two things the resolution maths will not fix
Aspect ratio. Square outputs do not fit any standard frame size. Cropping a 1:1 image to A3 proportions throws away roughly 30% of the pixels — which has to be counted before you decide the file is big enough. Generate in the proportions you intend to print.
Colour. Screens are backlit and additive; paper is neither. Saturated blues, bright greens and anything glowing will come back duller than they looked. That is a property of ink, not a fault in the file, and no amount of resolution changes it.
The pixel figures above are calculated from the stated print dimensions — centimetres converted at 2.54 cm to the inch, multiplied by the target ppi, rounded to the nearest pixel. You can check any row with a calculator.