π Aspect Ratio Calculator
Simplify aspect ratios and scale dimensions proportionally. Perfect for resizing images and videos to 16:9, 4:3, 1:1 and more.
Scale to a new size
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How aspect ratios work
An aspect ratio describes the proportional relationship between width and height. 16:9 (widescreen) is standard for YouTube and most monitors, 4:3 for older TV and presentation slides, 1:1 for Instagram and profile pictures, and 9:16 for vertical video such as Reels, Shorts and TikTok. Keeping the ratio while changing size prevents stretched or squashed images β enter one new dimension and the other is calculated automatically.