How do you put a big picture behind on your profile picture on facebook?

Answer 1

The short answer is 'get Timeline'. However I must remind you that there is significant dissatisfaction with the Timeline setup. Timeline will force you to relinquish certain aspects of your current setup which you may find more valuable than the Cover Photo, which goes at the top of your Timeline. You should find out more about the differences between Timeline and the old setup before switching.

To get Timeline, there should be a banner at the top of the wall advertising Timeline. There should be a button at the right end of the banner saying 'Get Timeline'.

Once you have Timeline, go to your Wall, and at the top, sure enough, behind your profile picture will be a blank space (though not strictly - it will instruct you in the middle of the blank space to click to add a Cover Photo). Click on the blank space to add the Cover Photo, and then select your picture.

An alternative for the old system, by which you will not be forced to convert to Timeline, is to use the 'Photos of You', which shows the five most recent pictures in which you are tagged. These come up at the top of your wall. To change what they show, you should create an album containing five pictures which, when put side by side, make a single image. This will not be as good as the Cover Photo, but the banner method is widely used to avoid subscribing to Timeline. If my explanation was too quick/general for you, there is likely to be a page somewhere which offers advice like this.

But before you subscribe to Timeline make sure you understand all the differences between the setup you're used to and the one you are about to get into.