FB: (NOTE: My page was taken down by FB so they are now trying to verify my identity...)
Profile Pic: 170x170 (desktop); 128x128 (mobile)
Header Image: 720x315
Max File Size: 100 KB
LinkedIn:
Logo Image: 300x300
Header Image: 1536x768
Max File Size: 100 KB
LinkedIn: Profile Pic: 400x400 Header Image: 1500x1500 Max File Size: 2 MB
Instagram: 320x320
FB: (NOTE: My page was taken down by FB so they are now trying to verify my identity...) Profile Pic: 170x170 (desktop); 128x128 (mobile) Header Image: 720x315 Max File Size: 100 KB
LinkedIn: Logo Image: 300x300 Header Image: 1536x768 Max File Size: 100 KB
More info HERE