get width of transformed: scaled element

get width of transformed: scaled element

I have 2 elemenets. One is scaled down in the CSS
.firstElement{
-webkit-transform:scale(.5,.5);
}
and the other is scaled inline by jQuery's
secondElement.animate({scale:.2, origin:[0,0])}
I need to get the width and height of the secondElement and the
firstElement in pixels after they are scaled down, and its needs to be
compatible cross browser. I tried everything, Im really not sure why I
cant get this. Anyone have any ideas? Thanks