What size do you consider to be a sheet cake? 1/2 sheet cake? Also how many do each serve?
TIA! Amber

I use the 11x15 for my half and two of those for the full sheet.

Depends on how large they cut the slices. The 11x15 I tell the people about 20 people.

The standard for bakeries is 9 x 13 is 1/4 sheet cake
12 x 18 is 1/2 sheet cake and two 12 x 18 is a full sheet cake. 9 x 13 is approx 20 - 24 pieces
12 x 18 i get 40 to 48 pieces and a full sheet cake is around 80 - 96 depending on how big you want the pieces. I make my the full depth of the pan plus. The higher end servings are only about 2", not very big. I don't recommend this many.
11X15 I do 24 to 30. 20 pieces would be a nice party size vs more servings for wedding etc.

12X18 is what I use for the 1/2 sheet also.

My sizes are the same as auntiecake, and the 11x15 some, including myself call a 1/3 sheet. It is different for everyone. The important thing is to get enough servings.

Wilma