I want to cover a cake in 50/50 fondant and modeling chocolate. I was wonder if substituting the weight on 1/2 the fondant for modeling chocolate will give me enough to cover my cake. I think modeling chocolate is quite a bit heavier than fondant and wasn't sure if I'd come up short?

I can't seem to find any way of estimating how much modeling chocolate it takes to cover any specific size of cake? or if just using the fondant estimate works fine for the 50/50 mix.

Thank you!