Hey all, I am a relative newbie, and cannot seem to find out how to calculate how much a 2 layer level of a cake will feed, filled and frosted? HELP!!!!!!! I am running out of time, and need to be able to calculate. thanks all! I appreciate any help!

I use the Wilton wedding guide for all tiered cakes.

http://www.wilton.com/cakes/cake-cutting-guides/wedding-cake-cutting-guide.cfm

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

As the PP stated, reference a serving chart.

Or, do some simple math.

The surface area of a serving of cake is 1x2 = 2.
Calculate the surface area of the cake: if square or rectangular, multiply length of two adjoining sides; if round multiply the diameter (size) of the round by 0.5, then multiply that result by itself, then multiply that result by pi (3.14).
Divide the surface area of the cake by the surface area of a serving of cake then round down to a whole number.