Aspect Ratio Calculator

How to use it

1. 1Enter the current width and height to see the simplified ratio.
2. 2If it matches a standard like 16:9 or 4:3, the name is shown next to it.
3. 3To resize, switch to the second panel and enter the ratio you want.
4. 4Fill in either the new width or the new height — the other is calculated to match.
5. 5Always let one dimension follow the other. Setting both by hand is what stretches an image.

Frequently asked questions

How do I resize an image without distorting it?

Change one dimension and let the other follow the original ratio, which is what the second panel here does. Setting both independently stretches the image, and stretched faces are immediately obvious.

Is 1366×768 really 16:9?

Almost, but not exactly. It reduces to 683:384, slightly wider than true 16:9. It was a common laptop resolution chosen for panel manufacturing reasons rather than mathematical tidiness.

What does 21:9 actually mean on a monitor?

It is a marketing label for ultrawide displays rather than a precise ratio. Common ultrawide resolutions such as 2560×1080 and 3440×1440 work out to roughly 2.37:1 and 2.39:1.

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