Managing your brand’s presence on so many different social channels can be a pain, and one of the annoying aspects of it is getting the right cover photos for each one. Facebook, Twitter, LinkedIn, Google+ — all have different guidelines for what the cover photo size should be.
Here is a list of official and unofficial references that will give you cover and profile picture specification for all social networks:
The cover photo of your Facebook page is very important: not only is it featured on your page, it is also prominently displayed in the user’s newsfeed when your page is recommended (paid or otherwise) by Facebook. Facebook’s official guidelines give very little detail but this page covers all you need to know.