Image & Photo-Editing Calculators
Free, practical calculators for the numbers behind editing images — resizing and aspect ratios, DPI and print size, megapixels, file size, and cropping to fit. Educational tools, not a substitute for your editor.
Image Resize Calculator
Resize an image while keeping its aspect ratio — set a new width and get the proportional height, or the reverse, or scale both sides by a percentage, all in whole pixels
Aspect Ratio Calculator
Reduce any width and height to its simplest ratio like 16:9 with the greatest common divisor, or solve for a missing dimension at a target ratio such as 16:9, 4:3, 3:2, or 1:1
DPI / PPI & Print Size Calculator
Turn pixels into a print size in inches and centimetres at any DPI, or turn a target print size into the pixels you need — the bridge between screen and paper
Megapixels & Resolution Calculator
Convert width × height into megapixels, or work back from a megapixel count and an aspect ratio to the pixel dimensions that hit it, with total pixels shown
Image File Size Estimator
Estimate a file's size from its dimensions, colour depth, and format — the exact raw bitmap plus a typical JPEG, PNG, or WebP compressed estimate in KB and MB
Crop & Aspect-Ratio Fit Calculator
Given a source size and a target ratio, find the largest centred crop that fills it, or the padded canvas and letterbox / pillarbox bars needed to fit the whole image