Image DPI & Print Size Calculator
How big can this image print before it looks soft? Three numbers, and any two give you the third.
This image at standard print sizes
| Print size | Effective DPI | Verdict |
|---|
What the DPI figures mean
| DPI | Suitable for |
|---|---|
| 300+ | Photo books, magazines, anything held in the hand |
| 200–300 | Good quality prints; the difference is hard to see at arm's length |
| 150–200 | Posters viewed from a metre away; large-format work |
| 72–150 | Banners and billboards viewed from several metres |
| Under 72 | Visibly soft unless viewed from a distance |
What the image DPI & Print Size Calculator does
DPI — dots per inch — is not a property of a digital image. An image has pixel dimensions and nothing else. DPI only becomes meaningful when you decide how large to print it, at which point it is simply pixels divided by inches. A 3000-pixel-wide image is 300 DPI printed at 10 inches wide, 150 DPI at 20 inches, and 75 DPI at 40 inches. The file never changed.
This calculator solves for whichever of the three you are missing. Give it pixels and DPI and it tells you the print size. Give it pixels and a print size and it tells you the effective DPI. Give it a print size and a target DPI and it tells you how many pixels you need — which is the version to use before a photo shoot, so you know what resolution to capture at.
The quality verdict is based on viewing distance rather than an absolute standard. 300 DPI is the traditional benchmark for print because it is roughly the limit of what the eye resolves at reading distance. A poster viewed from two metres away has no need of it: 150 DPI is fine, and large-format banners are routinely printed at 72 DPI or less because nobody stands close enough to see the difference.
The table shows your image at every standard print size at once, which is usually the fastest answer to the real question — how big can I print this? Read down until the verdict stops being acceptable and you have your maximum.
One thing no calculator can do is add detail. Setting a higher DPI in image software without changing the pixel count changes only a metadata field; setting it while resampling invents pixels by interpolation, which does not recover detail the camera never captured.
Print quality thresholds reviewed September 2026. They are conventions based on typical viewing distances rather than fixed standards, and commercial printers vary in what they require — always check your printer's own specification for a paid job.
How to use it
- Enter your image's pixel dimensions. The Image Resizer will tell you them if you are unsure.
- Choose what to solve for — print size is the usual question.
- Read the verdict, remembering that it assumes reading distance.
- Scan the standard-sizes table to find the largest print that still holds up.
A worked example
A 24-megapixel photo, 6000 × 4000 pixels:
| Print size | Effective DPI | Verdict |
|---|---|---|
| 10 × 8 in | 500 DPI | Excellent — more than the printer can use |
| A3 | 342 DPI | Excellent |
| A2 | 242 DPI | Good |
| A1 | 171 DPI | Acceptable — fine on a wall |
| A0 | 121 DPI | Soft up close, fine from two metres |
The top row makes the point about DPI being meaningless in isolation: 500 DPI is not better than 300 in any way you can see, because the printer cannot resolve it and neither can your eye. The extra pixels are simply discarded. Meanwhile the A0 row would look poor in a portfolio held at arm's length and perfectly good mounted on a wall — the same number, two different answers, decided entirely by viewing distance.
Frequently asked questions
Does changing the DPI in my image editor improve print quality?
Not by itself. If you change DPI without resampling, only a metadata field changes and the pixels are identical. If you change it with resampling, the software invents pixels by interpolation, which cannot recover detail that was never captured.
Is 300 DPI always required for printing?
No. 300 DPI is the convention for material held at reading distance, because that is roughly what the eye resolves there. Posters are fine at 150, and large banners are routinely printed at 72 DPI or less because of the viewing distance.
What is the difference between DPI and PPI?
PPI (pixels per inch) describes a digital image or screen; DPI (dots per inch) describes a printer's ink dots. They are used interchangeably in everyday conversation, and this calculator uses the common meaning: image pixels per inch of print.
How many megapixels do I need for an A3 print?
About 12 megapixels for a comfortable 300 DPI (roughly 3500 × 2480). At 200 DPI, around 5 megapixels is enough. Set the calculator to Pixels needed and enter your target size and DPI to get the exact figure.
Last reviewed and updated: 6 September 2026. Figures and assumptions on this page are checked whenever the underlying guidance changes.