The team from makeawebsitehub have put together this 2018 Social Media Image Sizes Guide which outlines all the current image dimensions and details for each social network, along with the image types to use.Every major social media platform is listed on here to ensure you’re up-to-date with social media platform optimization.
Source: 2018 Social Media Image and Video Sizes Cheat Sheet [Infographic] | Social Media Today
Boris Loukanov Web Mix 