Aspect Ratio Calculator

Convert width and height into ratios like 1:1, 4:5, and 9:16 used by social platforms.

16:9
Aspect ratio
1.78
Decimal
1920
Width
1080
Height

What this tool does

Aspect ratio mistakes create letterboxing, stretched faces, and UI collisions. This free calculator helps you translate relationships like 9:16, 4:5, and 16:9 into exact pixel targets before you design or export.

Plan the ratio first, then design. Fixing ratio after a full design pass usually means cropping something important.

How to use it

  1. 1

    Enter width and height in pixels.

  2. 2

    View the simplified aspect ratio (e.g. 16:9).

  3. 3

    Click a social media preset to load standard dimensions.

Ratios creators use constantly

9:16 for Stories, Reels, TikTok, Shorts. 4:5 for Instagram feed portraits. 1:1 for square grids and many product shots. 16:9 for YouTube thumbnails and horizontal video. Knowing these by heart saves time; the calculator catches edge cases and custom sizes.

Safe zones differ even when the ratio matches. Keep text away from edges on vertical video. Faces should sit center-weighted when circular profile crops are involved.

Workflow with the image resizer

Calculate the pixel pair you need, design or shoot with that framing, then resize/export with the image resizer. If you inherit a wrong-ratio asset, calculate the crop you can live with before you destroy the subject.

Common mistakes

Confusing orientation (portrait vs landscape) with ratio labels. Designing at 1080×1920 then exporting a square crop without checking. Assuming all “vertical” platforms share identical safe margins.

Tips

  • Save a preset list of your brand’s required sizes.
  • Check image dimension checker after export when clients are picky.
  • Read the image sizes guide when training a new teammate.

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Frequently asked questions

What aspect ratio is Instagram Reels?

9:16 vertical (1080×1920 px).

What is YouTube thumbnail size?

1280×720 px (16:9 aspect ratio).