I need a bit of help with serving sizes for a cake that I am making for my sons birthday. We have 25 adults and 12 children attending. I have looked at both the Wilton and Earlene's charts and the sizes and I still can't figure out if I will have enough. To me, I can't imagine cutting a 9 inch 2 layer cake into 22 or more pieces, especially if it is the only desert. The cake will be 2 tiers, and I was going to do a 6 inch 2 layer on top, and a 9 inch 2 layer on the bottom. For those who do this often, do you think this is enough, or, should I make it a bit bigger, like an 8 inch on top and 10 inch on bottom? I hate having tons of waste, but I would hate for there to be not enough.
Any advice would be greatly appreciated!

I think its plenty. Unless you are cutting huge chunks of cake to serve..most kids prefer icing, most adults prefer cake, give the kids the outer edges with the most icing, the adults the center (unless of course someone requests more icing )

Thanks ConfectionsCC

One thing to remember is that when you are using those chart numbers, you are not cutting wedges, but cake sqaures. I couldn't imagine cutting a 9in cake in to 22 wedges, but I can see cutting it into 22 retangles/squares. Though actually I use the wedding chart for everything, so I would get even more from it.

We live in a super sized world were we thing everything has to be huge pieces. A 1x2x4 serving of cake is really plenty of cake.

Also remember if you have other things, like chips and dips, ice cream with the cake or you aren't having the party in the middle of a meal time, you shouldn't need huge cake slices. People should come to enjoy some cake and what not, they shouldn't plan to become full off a piece of cake.

Using the wedding chart and the 6/9 combo you should get 441x2x4 slices.

As a good reference. I like this page
It shows you how many servings based on how big of a slice you cut.

http://larkcakeshop.com/CakeServeGuide2.pdf