DPI vs PPI, the 300 DPI standard and sizing for print.
Whether a photo prints crisp or pixelated comes down to resolution. This guide explains DPI, PPI and how to size images for print.
PPI (pixels per inch) describes a digital image's pixel density; DPI (dots per inch) describes a printer's output. In everyday use the terms are used interchangeably, and the practical question is the same: do you have enough pixels for the print size you want? The DPI Calculator converts between pixels, inches and DPI.
For sharp photo prints viewed up close, 300 DPI is the long-standing standard. At 300 DPI, a 4x6 print needs 1200x1800 pixels. Large-format prints viewed from a distance (posters, banners) can use far less — 150 DPI or even lower — because the eye can't resolve the difference at viewing distance.
Work backward from the print: the Print Size Calculator tells you how big you can print a given image at a chosen DPI, and the Required Resolution Calculator tells you the resolution you need for a target print size. If your image is short on pixels, you either print smaller, accept lower DPI, or upscale.
Enlarging an image adds pixels by interpolation, but it can't invent real detail — push too far and prints look soft. Modern AI upscalers do better than old methods, but starting with enough resolution always beats rescuing a small file. For important prints, capture or scan at the highest practical resolution.
For close-viewed photos aim for 300 DPI; for wall art and posters 150 to 200 DPI is usually fine; for billboards far less. Always check the longest dimension first, and remember that cropping reduces available pixels, which lowers the maximum quality print size.
PPI is an image's pixel density; DPI is a printer's dot density — used interchangeably in practice.
300 DPI for close-viewed photos; 150 to 200 for posters viewed from a distance.
About 1200x1800 pixels at 300 DPI.
Upscaling adds pixels but not real detail; results soften if pushed too far.
Yes — it removes pixels, lowering the maximum quality print size.