How Big Can I Print?

What PPI actually measures

PPI - pixels per inch - is not a property your file carries around. It is the result of a division you do at the moment you choose a print size: the pixels along one edge, divided by the inches you want that edge to be.

A 6000 × 4000 pixel file printed 20 inches wide is 6000 ÷ 20 = 300 PPI. The same file printed 40 inches wide is 150 PPI. Nothing about the file changed; the pixels are just spread over more paper. This is why "is my photo high resolution?" has no answer until someone says how big it is going on the wall.

The calculator above works the division backwards. You give it the pixels, and it tells you the largest print that still lands in each band:

• 300 PPI and above - Excellent. Sharp at any sensible viewing distance, including with your nose against the glass.
• 200-299 PPI - Good. The honest working range for most fine art prints. At normal hanging distances it is indistinguishable from 300.
• 150-199 PPI - Fair. Acceptable, and often the right call on a large piece, but softness starts to show if you walk right up to it.
• Below 150 PPI. We would want to talk about the size, or about scanning the original at a higher resolution instead.

Why "always print at 300 DPI" is bad advice

The 300 figure comes from arm's-length viewing. Normal eyesight resolves detail about one arcminute apart, which at 30cm works out near 300 PPI - so a photograph held in the hand, or a small print you lean into, genuinely wants that much information.

The moment the print is on a wall, the maths changes. Resolvable detail scales with distance, so a print seen from two metres needs roughly a sixth of the pixels per inch that the same print needs in your hands. This is not a compromise or a trade-off; it is simply that your eye cannot use the extra pixels from over there. Billboards are printed in the tens of PPI and look perfectly sharp from the road.

A practical guide, deliberately conservative because people do lean in to fine art:

Printer DPI is a different number to your image's PPI

These get conflated constantly, including by software that ought to know better. They measure different things.

Your image's PPI is how many of your pixels land in each inch of paper. The printer's DPI is how finely it can place ink droplets. Our printers lay ink down far more finely than any file's pixel grid, because it takes many overlapping droplets of a handful of inks to reproduce the colour of a single pixel.

So a higher printer DPI does not mean your file needs to match it, and you will never need a 600 PPI image. Once your file is comfortably inside the bands above, more pixels stop making a visible difference and only make the file slower to handle.

The same applies to the "DPI" field stored in an image's metadata. It is a suggestion for software about default print size, and changing it from 72 to 300 in an editor adds no detail whatsoever - it just changes the number in the box. Only resampling changes the actual pixel count, and that is upscaling.

What upscaling can and cannot do

The calculator has a 2× upscale toggle, which shows you the sizes that become available if we enlarge the file before printing. It is worth understanding what that actually buys.

Upscaling invents pixels. Modern machine-learning upscalers are genuinely good at it - they have learned what edges, fabric, foliage and skin texture tend to look like, so they can extend a pattern convincingly rather than just blurring it the way old bicubic interpolation did. What none of them can do is recover information that was never captured. Detail that fell between the sensor's photosites, or was lost to a soft lens or camera shake, is gone.

Upscaling tends to work well on:

• Clean, well-exposed files that are simply not large enough
• Subjects with texture rather than fine structure - landscape, foliage, fabric, weathered surfaces
• Moderate enlargements, roughly up to 2×

It tends to disappoint on:

• Heavily compressed files, where it enlarges the JPEG artefacts along with everything else
• Noisy high-ISO images, unless denoised first
• Fine text, fine lines and distant faces, where it can invent detail that is plausible but wrong
• Anything already soft from focus or motion blur

The order of preference is always the same: start with the largest original you have. A raw file beats the JPEG exported from it, an original scan beats a re-scan of a print, and if the original is physical, scanning it properly will beat upscaling a photograph of it every time.

The paper changes how much resolution you need

Resolution is usually discussed as though every print lands on the same surface. It does not, and the surface has a real say in how much fine detail survives.

A heavily textured cotton rag has visible relief - the fibres and the mould-made surface sit at slightly different heights, and ink spreads a little where it meets them. That surface is doing something desirable, giving the print depth and a hand-made quality, but it also softens the very finest detail. On a paper like that, the difference between 200 and 300 PPI is often invisible, because the paper is the limiting factor rather than your file.

A smooth baryta or a resin-coated photo paper is the opposite. The surface holds a crisp ink dot, so it shows everything the file has - including noise, compression artefacts and over-sharpening. Smooth papers reward high-resolution files and punish marginal ones.

In practice this means the paper choice and the size decision belong together, and it is one of the better reasons to look at a test print on the actual stock before committing to a large run. Our paper range covers both ends of that spectrum.