Aspect Ratio Calculator

Simplify a width and height into their aspect ratio (e.g. 1920×1080 → 16:9), or solve for a missing width or height given a target ratio. Free and private, right in your browser.

Find the ratio

Solve a missing dimension

Punch in any two dimensions or a ratio like 16:9 and this tool simplifies it or solves for the missing width/height, handy for scaling images, sizing video exports, or cropping a photo without distorting it.

How to use it

  1. Enter a known width and height, or a ratio like 16:9
  2. Add the one dimension you're solving for
  3. Read off the simplified ratio or calculated value instantly

Frequently asked questions

How do I find a missing value, like width when I know height and ratio?
Enter the ratio (e.g. 16:9) and one known dimension. The calculator solves for the other automatically, so typing height 1080 with ratio 16:9 gives you width 1920.
What's the simplified form of an odd ratio like 1920:1200?
The calculator reduces it to lowest terms using the greatest common divisor, so 1920:1200 simplifies to 8:5.
Does it work for non-screen uses like print or photo cropping?
Yes. It's just ratio math, so it works equally well for print sizes, frame dimensions, or crop proportions, not only video/screen resolutions.