Convert between aspect ratios for images, videos, and social media — change any field (width, height, or ratio) and the rest auto-fill. Free, instant, with presets for every platform.
An aspect ratio is just width divided by height. A 16:9 image is 16 units wide for every 9 units tall — at any size. This converter lets you pin two values and solve for the third: type a width to find the matching height for a given ratio, or type both dimensions to discover what ratio you have. The live preview on the right shows you the shape at scale.
aspect-ratio: 16 / 9 CSS values for video containers.