Aspect Ratio Calculator
Enter a width and height to get the simplified ratio (like 16:9 or 4:3), then lock that ratio to calculate a matching width or height from a known dimension.
Simplified ratio
16:9
Frequently asked questions
How is the ratio simplified?
The tool finds the greatest common divisor (GCD) of the width and height and divides both by it, the same method used to reduce a fraction to its simplest form. 1920x1080, for example, simplifies to 16:9.
How do I resize an image or video while keeping its ratio?
Check "Lock this ratio", choose whether you know the new width or new height, enter that known value, and the tool calculates the matching dimension so the overall shape stays identical.
What's a common use case for this?
Resizing images, videos or design mockups without stretching or squashing them, cropping to a target ratio like 1:1 for social media, or figuring out what height a 1200px-wide banner needs to stay 3:1.