AspectRatioTool.org

Social media image sizes

Social media platforms often prefer fixed ratios. Square posts use 1:1, portrait posts often use 4:5 and stories or reels use 9:16.

Using the right ratio before uploading prevents unexpected cropping.

This page gives practical ratio guidance for posts, reels, thumbnails and profile visuals.

Quick reference

RatioCommon use
16:9Video, YouTube, website heroes
1:1Square posts, profile grids
4:5Portrait social posts
9:16Stories, reels, vertical video