Aspect Ratio

Aspect Ratio is a free math & calculators tool that runs entirely in your browser — solve W:H ratios & resize. No upload, no account, no limits.

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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, never logged and never used for training — which also means the tool keeps working when you are offline.