Resolution from Aspect Ratio

Sizing a canvas, export, or thumbnail to a specific aspect ratio is one of those tiny tasks that derails creative work every time the math isn't 16:9 — doing 21:9 or 4:5 in your head is tedious and easy to fumble by a few pixels, and platforms re-scale anything that lands even slightly off-target, which loses sharpness for no reason. Designers most often trip on vertical formats: they default to 1080 wide for 9:16 instead of computing the matching height, and the result ends up sized for a slightly different vertical canvas than the platform expects.

This tool replaces the mental arithmetic with one input plus a four-resolution scale ladder (FHD / QHD / 4K UHD / 8K UHD) so you can choose a standard delivery target instead of an arbitrary odd-pixel result. It rounds every output to an even number because every consumer video codec rejects odd dimensions. Pair it with the Aspect Ratio from Resolution converter when you need to go the other direction — deriving a ratio from a known width × height — and the Video Bitrate Calculator once the resolution is fixed so you can size the upload bitrate.