Social Media marketing is tough because there are so many different networks to keep track of. Social networks are constantly changing the dimensions and requirements for image and text limits and it is difficult to find the right info. Social media managers working for brands and agencies complain that this is one of the biggest issues as they spend too much time tweaking and adjusting their brand assets to look correctly on social media networks.
The Allin1social team has decided to put them all together in 1 handy place so that social media managers can simply refer to this as the definitive guide for the right social media image dimensions for 2015. Here you can find dimensions regarding important channels such as Facebook, Twitter, Instagram, Google+, LinkedIn, Youtube and Pinterest in one, simple infographic.
Infographic source : http://www.allin1social.com/blog/infographic-social-media-image-sizes-cheat-sheet-in-2015/