Aspect Ratio Calculator

Calculate new dimensions while maintaining the same aspect ratio.

Runs entirely in your browser

Source Dimensions

x

Common Presets

Calculate New Size

How it works

Resize while keeping the same proportions.

1

Enter dimensions

Enter your source width and height, or pick a preset ratio.

2

Set new size

Enter a new width or height to calculate the other dimension.

3

Get the result

The matching dimension is calculated instantly to preserve the ratio.

Why use KepTools Aspect Ratio Calculator?

Live calculation

Results update instantly as you type -- no button needed.

100% private

All calculations happen locally in your browser.

Common presets

Quick buttons for 16:9, 4:3, 1:1, 21:9, 3:2, and 9:16 ratios.

No account needed

Just open the page and start calculating. No sign-ups or logins.