Image Aspect Ratio Finder

How to use

1. 1Drop an image onto the upload area, or click it to pick a file from your computer.
2. 2Read the headline ratio (for example 16:9), the exact pixel size, orientation, and megapixels.
3. 3Check the closest standard match: an exact match is highlighted, otherwise the deviation percent shows how far off you are from the nearest named ratio.
4. 4Use the details grid to copy the simplified ratio, decimal, percent, or CSS aspect-ratio value.
5. 5Open the scoreboard to see the exact center-crop pixel size for every target ratio so you know what to crop to next.

About this tool

Image Aspect Ratio Finder reads any image you drop in and reports its true aspect ratio from the decoded pixel dimensions. It shows the simplified W:H (using the greatest common divisor, so 1920x1080 becomes 16:9), the exact decimal ratio (1.7778:1), the inverse ratio, the height as a percent of width, the CSS aspect-ratio value, megapixels, orientation, and the file size on disk. A scoreboard of twenty standard ratios (1:1, 16:9, 9:16, 4:3, 3:2, 21:9, 1.91:1 for Open Graph, 1.85:1 and 2.39:1 for cinema, the golden ratio, and more) is sorted by how close your image is, with deviation percent and the exact center-crop dimensions needed to hit each target without scaling. JPG, PNG, WebP, GIF, AVIF, SVG, BMP, and TIFF are supported. SVG files fall back to width, height, or viewBox values when the rasterizer reports zero dimensions. Everything runs locally in your browser through FileReader and HTMLImageElement, so the bytes never leave your device.

Free to use. Works in your browser. No signup, no login.