ASPECT RATIO
Aspect ratio calculator, simplify and scale in one place.
Get the simplest ratio for any width and height, solve for the missing dimension from a target, and pick from common video and paper presets. Runs locally in your browser.
Dimensions & ratio
Solve for a target size
The result is written back into width/height, keeping the ratio.
Common presets
Everything runs locally in your browser
What can this tool do?
Enter any width and height to instantly get the simplified integer ratio (1920x1080 becomes 16:9), the decimal ratio and the width/height percentages, plus a visual diagram. Choose to solve by width or height and enter a target value to compute the missing dimension while preserving the ratio — handy for thumbnails, screen fitting and print sizes. Presets include 16:9, 4:3, 1:1, 21:9, 3:2, 9:16 and A4/A3 paper. Everything runs locally.
FAQ
How is the simplest ratio calculated?
Divide both numbers by their greatest common divisor; the two coprime integers left are the simplest ratio. 1920 and 1080 share 120, giving 16:9.
Are 16:9 and 1920x1080 the same thing?
Same ratio, different size. 16:9 is the ratio; 1920x1080 is one resolution using it — 1280x720 and 3840x2160 share that ratio too.