Aspect Ratio Calculator

The Aspect Ratio Calculator is an online tool that automatically computes aspect ratios from width and height values using the GCD (Greatest Common Divisor) algorithm for the simplest form.

Common aspect ratios depend on the use case: 16:9 for Full HD and 4K video, 2.39:1 for cinema, 3:2 and 4:3 for photography, and 1:1 or 9:16 for social media content. Presets and lock-ratio calculations help decide image sizes, video sizes, and responsive design dimensions.

Enable ratio lock to calculate the missing dimension from just one input. Adjust decimal precision (2–4 decimal places) to suit your needs, and share results instantly via generated links. Results display both the simplified ratio (e.g., 16:9) and decimal ratio (e.g., 1.78), with common resolutions for each ratio automatically provided.

All processing occurs in your browser, so the entered dimensions can be checked without server-side uploading. When you want to create an image from the calculated ratio, use [Aspect Ratio Resizer](/en/image/aspect-ratio-resizer/) or [Image Resizer](/en/image/image-resizer/). For cropping, try [Image Crop Tool](/en/image/image-crop-tool/). For video workflows, [Video Aspect Ratio Changer](/en/movie/video-aspect-ratio-changer/) and [Video Resizer](/en/movie/video-resize/) can help.