I am making a full sheet cake and a half of sheet cake to make one big cake. I just am trying to figure out how much buttercream I am going to need to make. Any ideas please let me know.
hopefully this chart will help, remember this chart has amounts for 4" tall cakes, so you should have plenty if you have this many cups ready.
The amount would really depend on how thick you like your buttercream on your cakes. Are you torting and filling with buttercream? If they are single layer no torting I would problably start out with about 6-8 lbs. I like to make my frosting in batches and put in a small bucket. Once I have made a bit more than I think I may need- then I fill my mixer to the top and mix my frosting- this way I have a smooth (very little bubbles) frosted cake. If you are able to make it the night before and have ready you will enjoy the decorating a whole lot more.