Aspect Ratio Calculator
Enter a width and height to get the simplified aspect ratio (like 16:9), then use the resize row to find a new width or height that keeps the same proportions.
How to use
Type the original width and height — the ratio and its decimal value appear instantly.
In the resize section, enter a new width to get the matching height (or vice versa) so nothing gets stretched. Great for images, video and screens.
FAQ
What is an aspect ratio?
It's the proportional relationship between width and height, written as W:H — 1920×1080 simplifies to 16:9.
How do I resize without distortion?
Keep the aspect ratio: enter one new dimension and let the tool calculate the other, so the image scales without stretching.
What are common ratios?
16:9 (widescreen video), 4:3 (older screens), 1:1 (square), 21:9 (ultrawide), 3:2, and 9:16 (vertical/phone).
Does it work for any units?
Yes — pixels, cm or anything else. The ratio depends only on the proportion, not the unit.