Image size and resolution

Find the dimensions that matter for your screen, print or upload.

Image pixels and resolution, explained

Separate pixel dimensions, display size and print density. See what a 2400 × 1600 image actually tells you.

PPI describes image pixels per inch. DPI describes printer dots per inch. Use pixel dimensions for image-size calculations.

Divide pixels by PPI to find the print size. Work through an example and allow for the pixels lost to cropping.

Aspect ratio describes shape, not resolution. Reduce width and height to a ratio and compare common print and screen shapes.

Resizing changes image dimensions, cropping removes edges and padding adds space. Choose the operation that matches your goal.

Upscaling adds output pixels. It does not prove that missing original detail has returned. Check the source before enlarging.

Calculate megapixels from width and height. See why two images with the same count can have different shapes and quality.

Pixels describe dimensions; bytes describe storage. Learn why equal-sized images can have different file sizes.

Find pixel dimensions for 4 × 6, 5 × 7, 8 × 10 and larger prints at 150 or 300 PPI.

Calculate raster image dimensions for a display size without confusing screen pixels with print PPI.