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Aspect ratio calculator for social video and images

Two calculations sit behind the same question: resize something to a ratio, or identify the ratio of a size you already have.

Editing either field recalculates the other at 9:16. Used for reels, tiktok, shorts, stories.

Calculated in your browser. A ratio tells you the shape, not the export size: check the platform's current pixel and file-size guidance before you upload, and keep text away from the edges where a feed may crop.

Ratio is the shape, size is the resolution

A ratio describes proportions and nothing else. 1080 by 1920 and 720 by 1280 are both 9:16, and both will fill a phone screen without cropping; one is simply sharper than the other. Confusing the two is what produces an export that fits perfectly and looks soft.

Get the ratio right first, because that is what decides whether a feed crops your image. Then pick a resolution high enough that the platform's own compression has something to work with, which in practice means exporting at least as large as the largest surface the image will appear on.

The ratios that cover almost everything

Ratios are stable. Recommended pixel dimensions and file caps are not, and are maintained separately on the image sizes reference rather than duplicated here where they would go stale.
RatioShapeWhere it is used
9:16Tall, full phone screenReels, TikTok, Shorts, Stories
4:5Portrait, the tallest the feed allowsInstagram feed posts, where it takes the most vertical space
1:1SquareFeed posts across most networks, profile grids
16:9LandscapeYouTube, embedded and desktop-first video
1.91:1Wide letterboxLink previews and Open Graph cards

Leave room for the crop you did not plan for

  • Keep text and faces away from the outer ten percent. A feed that crops a 4:5 image to a square takes it from the top and bottom.
  • A 9:16 video gets interface drawn over it. Captions, the username, and the action rail all sit on top of the lower and right edges.
  • Export one 1:1 and one 9:16 rather than a folder of per-platform crops. Those two cover most destinations, and a 4:5 covers the rest.
  • Check the exported file, not the design canvas. Rounding in an export pipeline can move a 1080 by 1350 to 1080 by 1349, which is no longer 4:5 and will be re-cropped.