The cover photo is the large one at the top of your Google+ Page. It’s displayed at an aspect ratio of about 16:9, the same as the HD video standard. On desktop screen sizes, your image will display on the right, and the left is an automatically semi-transparent overlay under your profile picture.
Google+ uses a responsive layout that adjusts for different-sized screens, the actual size that it’s displayed at varies quite a bit. The largest your image displays at is 1080 x 608 px. The semi-transparent part on the left also re-sizes, and duplicates part of your image.
The ideal size for the image you upload is 1080x608px (aspect ratio of 135:76, which is very close to 16:9). The smallest image you can use is 480 x 270 px (aspect ratio of 16:9), and the largest image you can use is 2120 x 1192 px.
The Google+ Cover Photo PSD Template we provide is 1080 x 608 px and is shown below. That’s right, we don’t make you signup for our newsletter to download a simple template. Just download it, get your cover photo looking awesome, and then if it helped you, let your friends know where you got it. (Yes, that was my shameless self promotion plug.)
Your profile image will be shown as a circle with a 120 px diameter. Bigger photos look better. The smallest size you can use for your profile picture is 250 x 250 px.
You are free to choose any type of image for your profile picture (as long as it doesn’t violate Google’s terms of service). Google recommends that you use “a good, recognizable head-shot”, but as you can see we chose something a bit different. It’s really up to you to be creative, and make it fit within a 250 px diameter circle.
So that’s it, now you can easily create your own Google+ Cover Photo. Be sure to check out our other posts for Facebook, Twitter, and LinkedIn.