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Aspect Ratio Calculator

Simplify width and height to an aspect ratio and scale dimensions proportionally.

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About the Aspect Ratio Calculator

The Aspect Ratio Calculator reduces a width and height to their simplest ratio, such as 1920×1080 to 16:9, and can scale dimensions while keeping that ratio. Enter a new width or a new height and it calculates the matching other side.

Everything runs in your browser with JavaScript. Nothing you type is uploaded to our server, so it is safe to use with private data.

How to use it

  1. Enter the original width and height.
  2. Optionally enter a new width or height.
  3. Select Calculate ratio.

Common uses

  • Sizing videos and thumbnails for different platforms.
  • Resizing images without distortion.
  • Checking screen and print proportions.

Tips

  • Common ratios: 16:9 for video, 4:3 for older screens and many photos, 1:1 for square posts, 9:16 for vertical video.
  • Round the scaled result to whole pixels when you use it.