The honest answer is that a 24 megapixel file prints a 40 × 60 cm picture beautifully, with pixels to spare, and that most people asking the question already have more resolution than they need. The interesting part is why, and where the real limit actually sits, because it is not the number printed on the side of the camera box.
Pixels are not a size until you choose one
A file has no physical dimensions. It is a grid of pixels, and it becomes 10 × 15 cm or 80 × 120 cm only at the moment somebody decides how densely to lay that grid onto paper. That density is dots per inch, DPI, and it is the only number in this whole subject that matters.
The arithmetic is one line. Divide the pixels along an edge by the length of that edge in inches. A 6000 pixel edge printed 60 cm long is 6000 divided by 23.6, which is 254 DPI. Print the same file 90 cm long and the same pixels spread further: 169 DPI. Nothing was lost. The paper simply got bigger while the file stayed the same, which is what the drawing beside this is doing.
So there is no such thing as a file being big enough. There is only a file being big enough for a particular size, and the question is always what happens as you push past it.
The number nobody quotes is how far away you stand
300 DPI is the number people repeat, and it comes from print work held at reading distance: a magazine, a book, something 30 cm from your face. At that distance the eye resolves roughly 300 separate things per inch and no more, so 300 DPI is where adding pixels stops buying anything at all.
A picture on a wall is not held at reading distance. A 40 × 60 cm print is looked at from a metre or more, and at a metre the eye resolves about 150 DPI. At three metres it is nearer 75. This is not a trick or a compromise; it is the reason a billboard printed at fifteen dots to the inch looks perfectly sharp from a car, and it is why large prints are made from files that would embarrass a magazine.
The practical rule that falls out of it: the bigger the print, the further away it is seen, and the fewer pixels per inch it needs. Print size and required density pull in opposite directions, which is the quiet reason big prints are far more achievable than the 300 DPI folklore suggests.
Where 200 DPI comes from
The catalogue lists, for every photograph, the sizes it prints at 200 DPI or better after cropping to that shape. 200 is a deliberate choice. It is well above what the eye can pick out at wall distance, so it holds up even when someone walks right up to the frame and puts their nose against it, which people do with a photograph they have just bought.
That list is where quality stays excellent. It is not a ceiling, and it is worth being clear about this, because a lot of shops present it as one. You receive the full file. Print it larger whenever you like: the picture softens gradually as the density falls, it does not fail at any particular number, and canvas in particular is routinely printed well beyond the list, because the weave is coarser than the pixels and the thing is viewed from across a room. The only hard bound anywhere on this site is the licence, which is a legal term rather than a property of the file.
Cropping is where the pixels actually go
Resolution is rarely lost to the print size. It is lost before that, to cropping, and cropping is more expensive than it feels, because area falls with the square. Trim 10% off each edge and 19% of the file is gone. Trim 20% and you are down to 64% of the pixels you started with.
Aspect ratio does the same thing without anyone deciding to. A camera shoots 3:2. A 40 × 60 cm print is 3:2, so that one costs nothing. A 50 × 70 cm print is not, and fitting a 3:2 frame into it throws away about 7% of the long edge before a single drop of ink is laid down. Square prints are the worst of it: a third of a 3:2 frame has to go.
This is why the print-size table on each photograph is crop-aware rather than a straight division. It refuses any size that would cost more than 18% of the long edge, because a size you can only reach by butchering the composition is not really a size the picture prints at.
Which is why the files come in several shapes
Every photograph in the shop is delivered as more than one file. There is a square crop, a 3:2, and a wider one, each rendered from the full-resolution original rather than trimmed out of an export afterwards. That matters for exactly the reason above: a square made properly from the original keeps far more pixels than a square cut out of a 3:2 JPEG at home.
So when the table on a photograph says it prints well at a size, it has already checked all of the delivered crops and taken the one that suits that shape. You do not have to do the arithmetic. Pick the shape that matches your frame and print it.
The numbers, if you want them
Two columns, because there are two honest answers. 200 DPI is the fine-art standard, sharp from any distance including none. 300 DPI is the point past which no eye can tell the difference at any distance whatsoever, and is worth aiming at only for small prints held in the hand.
| Print size | At 200 DPI | At 300 DPI | Needed |
|---|---|---|---|
| 10 × 15 cm | 787 × 1181 | 1181 × 1772 | 0.9 MP |
| 20 × 30 cm | 1575 × 2362 | 2362 × 3543 | 3.7 MP |
| A4 · 21 × 30 cm | 1654 × 2339 | 2480 × 3508 | 3.9 MP |
| 30 × 40 cm | 2362 × 3150 | 3543 × 4724 | 7.4 MP |
| A3 · 30 × 42 cm | 2339 × 3307 | 3508 × 4961 | 7.8 MP |
| 40 × 60 cm | 3150 × 4724 | 4724 × 7087 | 14.9 MP |
| 50 × 70 cm | 3937 × 5512 | 5906 × 8268 | 21.7 MP |
| 60 × 90 cm | 4724 × 7087 | 7087 × 10630 | 33.5 MP |
| 80 × 120 cm | 6299 × 9449 | 9449 × 14173 | 59.5 MP |
Read the last column against the wall, not against the spec sheet. A 24 megapixel file clears 40 × 60 cm comfortably and prints 60 × 90 cm at 169 DPI, which on a wall is a photograph nobody would ever question. The table says where the arithmetic is flawless, not where the picture stops working.
So, the 40 × 60 cm print
14.9 megapixels at 200 DPI, uncropped. Any camera made in the last fifteen years clears that, most phones clear it, and every photograph in this shop clears it with room left over. If you are choosing a file to print at that size, the resolution is almost certainly not what will decide whether you like the result.
What will decide it: whether the picture was sharp when it was taken, whether it was exposed well enough that the shadows are not full of noise, and what it is printed on. A soft file at 400 DPI is a soft print. A crisp file at 180 DPI is a crisp print. No amount of resolution rescues a photograph that missed focus, and no reasonable shortage of it ruins one that did not.
When you genuinely are short
It happens, usually with an old file or a heavy crop. Three things to do, in order. Print it smaller, which costs nothing and is always the right first move. Print it on a surface that hides the shortfall: canvas, textured rag, anything with a tooth of its own. Or upscale it, which modern tools do well enough for a wall, though they invent detail rather than recovering it, so judge the result at the size you will hang it rather than at 100% on a screen.
What not to do is print small and hope. A picture short of pixels looks worse at 20 cm held in the hand than at 80 cm hung across a room, because the hand is where the eye can still count them.
The short version
- Pixels have no size. DPI is pixels divided by inches, and it is the only number.
- 300 DPI is for things held in the hand. Wall prints need far less.
- 200 DPI is the standard used here: excellent from any distance, and not a ceiling.
- A 40 × 60 cm print wants 14.9 MP uncropped, which almost everything has.
- Cropping costs area, not length. 20% off each edge spends over a third of the file.
- Sharpness at capture beats resolution every time.