I know this is such a basic question. I have been making cakes for nine years and I eyeball everything now, but am about to teach a class and would like something to present my students with. Can anyone direct me to an icing chart of some kind, thanks. Just for rounds and squares is okay.
Thanks all :-}

Wilton has a chart that give amount of batter required for cake pans and icing to cover as well.

http://www.wilton.com/cakes/making-cakes/baking-wedding-cake-2-inch-pans.cfm