Aspect Ratio Calculator: Resize Images and Videos Without Distortion
Aspect ratio is the proportional relationship between the width and height of an image or video. It is expressed as two numbers separated by a colon, such as 16:9 or 4:3. Maintaining the correct aspect ratio is critical when resizing media — if you change width without adjusting height proportionally, the image becomes stretched or squished.
Our aspect ratio calculator takes a width value and instantly computes the corresponding height for all common aspect ratios. This is invaluable for web designers setting responsive image dimensions, video editors exporting at the right resolution, or social media managers preparing content for platforms with specific dimension requirements.
The most widely used aspect ratio today is 16:9, the standard for HD and 4K displays, YouTube videos, and most streaming content. The 4:3 ratio was the old television standard and is still used in some presentations. The 1:1 square format is popular on Instagram, while 9:16 vertical is essential for Stories, Reels, and TikTok.
You can also enter a custom ratio for specialized needs. Photographers often work with 3:2 (the standard 35mm film ratio) or 5:4 for print formats. Ultrawide monitors use 21:9 or even 32:9. Simply enter your desired width, and the calculator shows the exact pixel height for each ratio.