Question 1

How do I calculate a matching width or height for an aspect ratio?

Accepted Answer

Enter your target aspect ratio (or pick a preset), then type in one known dimension; the tool calculates the matching value instantly so both sides keep the same proportion.

Question 2

Can it reduce given dimensions into a simplified ratio?

Accepted Answer

Yes. Enter a width and height and the tool reduces them to their simplest ratio, for example turning 1920x1080 into 16:9.

Question 3

Which preset should I use for common screens and video?

Accepted Answer

Use 16:9 for most modern displays and HD/4K video, 4:3 for older screens, and 1:1 for square images; if none fits, enter your own custom ratio instead.

Question 4

Is the calculator free and does it work offline?

Accepted Answer

Yes, it is completely free with no account required, and because all calculation runs in your browser it keeps working once the page has loaded even without a connection.

Question 5

Are the dimensions I enter sent to a server?

Accepted Answer

No. The width, height, and ratio values you type stay on your device and are calculated locally in the browser, with nothing uploaded or tracked.

Aspect Ratio Calculator

Height from width

Width from height

Ratio from width × height

FAQ