Megapixels and print size.

Worked example

A 6000 × 4000 px photo is 6000 × 4000 ÷ 1,000,000 = 24 MP, a 3:2 ratio. At 300 ppi it prints 20 × 13.3 in (50.8 × 33.9 cm); at 150 ppi it prints 40 × 26.7 in. An 8 × 10 in print at 300 ppi needs 2400 × 3000 px (7.2 MP).

How it works

Megapixels = width × height ÷ 1,000,000. Print size (inches) = pixels ÷ ppi, and 1 inch = 2.54 cm. The aspect ratio is the width and height divided by their greatest common divisor. For a print size, pixels needed = inches × ppi, rounded up.

No ppi value is correct for every print. It is a viewing-distance and printer decision, so it is an input here. If the aspect ratio of your photo differs from the paper (3:2 vs 4:5, for example), the print will need cropping or borders; this tool does not crop.

Printing on canvas and want the aspect-ratio crop and gallery wrap worked out? Use the photo to canvas print calculator.

Sources and basis (checked 2026-10-05): arithmetic on the numbers you enter (pixels ÷ ppi; 1 in = 2.54 cm, the international inch). No external data.

FAQ

How many megapixels do I need for an 8x10 print?

At 300 ppi an 8 × 10 in print needs 2400 × 3000 px, which is 7.2 MP. At 150 ppi it needs 1200 × 1500 px, 1.8 MP.

How do I convert pixels to inches?

Divide the pixel count by the ppi. 3000 px at 300 ppi is 10 in.

What is the difference between ppi and dpi?

PPI counts image pixels per inch of print. DPI counts printer ink dots per inch. The two are related but not the same thing.

Is more megapixels always better?

More pixels allow a larger print at the same ppi or more cropping room. They do not improve a soft or noisy photo.

Does this resize my image?

No. It only does arithmetic in your browser; no file is opened or uploaded.