I have a "sweet 16" cake to do this week, and it's the largest cake i've done before. I'm not sure exactly how much icing and fondant i'll need to cover one 4in., two 6in., & one 9in. hexagon cakes, and one 6in. & one 12in. round cakes..

Does anyone know how many cups of icing and lbs. of fondant I'll need to cover it?

Wilton has charts that give you amounts for batter and icing.

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

Global Sugar Art has a chart for fondant.

http://www.globalsugarart.com/?id=24