So how do you figure out the padding-top for say an image thats 1127.34591.44? Two common video aspect ratios are 4:3 One way is using the CSScalc(), like this: If youre using a preprocessor like Sass, we could do the calculation ahead of time: Its a cinch to make iframes responsive with an aspect ratio box using the intrinsic ratio technique. WebBootstrap 5 Ratio / Embed utilities Create responsive video or images based on the width of the parent by creating an intrinsic ratio that scales on any device. How to embed an swf file having controls like video/audio Tag? Wrap any embed like an