Aspect Ratio Calculator

Reduce any dimensions to a ratio, and scale sizes proportionally.

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Two jobs in one: identify the ratio of any dimensions (1920×1080 reduces to 16:9, matched against the common standards), and scale to a new size — enter a target width and get the height that keeps proportions exactly. The everyday cases: video embeds, responsive images, thumbnails and print sizing.

Frequently asked questions

What are the standard aspect ratios?

16:9 for video and screens, 9:16 vertical for Stories/TikTok, 4:3 classic, 3:2 photography, 1:1 square, 21:9 ultrawide. The calculator names the match when your dimensions hit one.

How do I resize without stretching?

Scale both dimensions by the same factor: new height = new width × (original height ÷ original width). That's the calculation the scaler does — distortion comes from changing one dimension independently.

Why does my 1366×768 screen show as 683:384?

Because that's the exact reduced ratio — 1366×768 is only approximately 16:9 (which would be 1365.33×768). Marketing rounds; arithmetic doesn't. It's close enough that 16:9 content fits fine.