Is there any way I can get the height of a specific div class/id? I've given up on trying to figure out why the sidebar keeps moving, so instead I've decided to just position it and the post divs a certain space from the top. So I was wondering if there is some kind of tag or code I can use to get, first, the height of my #masthead div, and second, some kind of if/else code so that the posts don't load on top of each other (like, if already a post, get height, add height to #masthead's height; this far from top, else, #masthead's height from top).
When I type it all out it sounds much more complicated than it did in my head. I've checked the codex, but haven't found anything yet.