Solve width and height for any aspect ratio, like 16:9.
Loading Aspect Ratio…
How to use Aspect Ratio
Open the Aspect Ratio tool.
Paste or type your number into the input field.
The output updates as you type. Adjust the options if you need a different format.
Copy the result, or share the URL to hand the exact input to someone else.
About Aspect Ratio
Work with aspect ratios. Enter a width and height to get the simplified ratio and decimal, snap to common presets like 16:9 or 4:3, and resize to a new width while keeping the ratio, with a ready-to-paste CSS aspect-ratio value.
What people use it for
Find the simplified aspect ratio of a resolution like 1920×1080.
Calculate the height for a new width that keeps 16:9.
Get the CSS aspect-ratio value for a responsive box.
Frequently asked questions
Can it resize while keeping ratio?
Yes. Enter a target width and it computes the matching height for the current ratio.
Does it output CSS?
Yes, it gives a copy-ready 'aspect-ratio: W / H;' declaration.
Is it private?
Every calculation happens on this page, in your own browser. Your input is never sent to a server and never logged, which also means the tool keeps working when you are offline.