More to explore:
Cake sizes servings. Double the numbers for wedding cake servings which are typically half the size of a birthday slice.
Helpful Cake Serving Size Chart, although I'm not sure this is what most wedding cake decorators go by.
This is not accurate for most wedding cake bakers. An 8" cake serves 15 servings of 1" wide x 2" long x 4" high (10" serves 30). WEDDING: If you are cutting cake away from guests, get a smaller decorative cake and a large sheet cake in back. Saves a TON of money. Guests will never know the difference.
Cake pan serving sizes - this is so helpful!
cake size serving chart