Thanks to my friend Ray Hiltz, who sent me a link to this article on How to Optimize Your Profile Photos Across Social Media, the highlights of which I’ve summarized here below. Worth checking out the full article if you are a professional photographer and/or just looking to have your profile photo looks its best on the most popular social media platforms.

One big happy family

One big happy family

Facebook:

  • Profile pics are displayed at 160 x 160 pixels, but the image you upload must have minimum measurements of 180 x 180 pixels.
  • Cover photos should be 851 pixels wide, 315 pixels tall and less than 100KB

Twitter:

  • Maximum file size for a Twitter avatar is 2MB, though it will show only as 73 x 73 pixels on your profile page and a very small 48 x 48 pixels in tweets
  • Header photos can be up to 5MB in size; the recommended dimensions for these images are 1252 x 626 pixels

Google+:

  • consider what kind of image will work in a round format as the default form in Google+ circles is well, a circle
  • avatar displays 120 x 120 pixels on your profile, but not all of that will show up due to the round crop
  • Post images will be as small as 48 x 48 pixels and just 28 x 28 in comments

You Tube:

  • Since Google owns You Tube, the same image requirements for Google+ apply, however unique to the You Tube platform is cover photo You Tube calls “channel art” for which the recommendation is to upload a 2560 x 1440 pixel image

LinkedIn:

  • Max file size of 4MB
  • Upload a square JPG, GIF or PNG (default size for a LinkedIn avatar on your profile page is 200 x 200 pixels, but users can click to enlarge the image up to 450 x 450 pixels).
  • Company logos on company pages display on LinkedIn pages at 100 x 60 pixels, and the square logo is 50 by 50 pixels. You can also upload a homepage cover photo-style image to a company page. The minimum recommended size is 646 x 220 pixels.

As mentioned above, this summary is taken from an article on Mashable, worth checking out for more ample detail on the content quoted above.