About this tool
Print Size / Megapixel / DPI Calculator is a free, in-browser tool that turns pixel dimensions into a physical print size, or tells you how many megapixels a target print needs at your chosen print resolution. Nothing is uploaded — every figure is computed locally as you type.
From pixels, the print size in inches is simply pixel width ÷ DPI and pixel height ÷ DPI (multiply by 2.54 for centimetres), and the sensor megapixels are width × height ÷ 1,000,000. From a target print, the pixels needed are width × DPI by height × DPI, and the megapixels needed are that pixel count ÷ 1,000,000. DPI here means dots (pixels) per inch of paper — the print resolution, not on-screen PPI.
Use it to check whether a file is big enough for a poster before you send it to the lab: 300 DPI is the standard for sharp photo prints, while large prints viewed from a distance look fine at 150–200 DPI.
Frequently asked questions
How do I get the print size from my pixel dimensions?
Divide each pixel dimension by the DPI. A 6000 × 4000 pixel image at 300 DPI prints 20 × 13.33 inches (50.8 × 33.87 cm). Lower the DPI and the print gets bigger, but detail per inch drops.
What DPI should I use for photo prints?
300 DPI (or PPI) is the accepted standard for sharp prints held at reading distance. Fine-art and small prints sometimes target 360 DPI; large banners and posters viewed from metres away are fine at 150–200 DPI.
Is DPI the same as the PPI on my screen?
No. This tool computes print output resolution — pixels spread across inches of paper. On-screen PPI depends on the display's pixel density and viewing size, which is a different calculation.
Does the calculator upload my image?
No. You only enter numbers — pixel dimensions or print size and DPI — and everything is computed in your browser. No file is ever uploaded.
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