Aspect Ratio Calculator

A free online conversion calculator that calculate aspect ratios from dimensions or presets. Get accurate results instantly without any software installation. Aspect ratio calculations are critical for video production, UI design, photography cropping, and print layout: matching a 16:9 thumbnail, preserving a 4:3 sensor crop, or fitting content into a 21:9 ultrawide banner without distortion. Guessing dimensions by eye leads to stretched images and letterboxing artifacts. Enter any two dimensions (width and height) to get the simplified ratio, or choose a common preset (16:9, 4:3, 21:9, 1:1) and calculate the matching dimensions for any target resolution. Pixel-perfect results for video, display, and print. Enter any two dimensions or pick a common ratio preset (16:9, 4:3, 1:1, 9:16, 21:9) and the tool computes the matching width, height, and exact ratio in reduced form. A visual preview rectangle shows the proportions graphically. Ratio reduction and dimension math run as pure JavaScript arithmetic within the page. Design specifications and unreleased product dimensions are never sent to any server, keeping proprietary creative work private.