How to Calculate and Scale an Aspect Ratio
Published September 21, 2026 · 2 min read
Resizing an image or video while keeping its proportions correct means knowing its exact aspect ratio — and calculating the matching height for a new target width. This tool does both in one step.
Try Aspect Ratio CalculatorSteps
- 1
Open the Aspect Ratio Calculator tool
Go to the aspect ratio calculator.
- 2
Enter your current width and height
Type the original dimensions.
- 3
See the simplified ratio
The tool reduces it to its simplest form, like 16:9.
- 4
Enter a target width or height
Get the matching dimension that keeps the same proportions.
Frequently asked questions
It's reduced using the greatest common divisor of the width and height, giving you the simplest possible whole-number ratio, like 1920×1080 simplifying to 16:9.
Yes — enter either a target width or a target height, and the tool calculates the other dimension needed to preserve the original proportions.
Common uses include resizing images or video without distortion, and figuring out standard ratios (like 4:3 or 16:9) for design or video layout planning.
Because the math is instant, this avoids resizing an image by trial and error and accidentally stretching it out of proportion.