I'm having a total brain flerp. Can someone PLEASE help me?! I just need to know how many a 8" single layer cake will feed...

Do you really mean a single layer? Or do you mean a single tier (usually 2 layers).

See: http://www.wilton.com/cakes/cake-cutting-guides/wedding-cake-cutting-guide.cfm
http://www.wilton.com/cakes/making-cakes/baking-party-cake-2-inch-pans.cfm

Ultimately, it depends on how you cut the cake - what size the pieces are.

Yes...I mean a single layer...will be just over 2" high once torted. That's all they want. Thank you for the links

As I remember an 8"x4" serves 25 so out of a single layer I'd say they can get 10-12 servings. If you treat the round as if it were a sq and come in 2" and slice the whole piece, lay it down and cut that into 2" slices you should be 16 pieces. Most people are going to cut it like a pie and then only get the 10 or so.

About 10 party servings

Thank you all!