Question: how big is a sheet cake?
Answer: Full sheet cake = 18 x 24 x 2 inches or 18 x 26 x 2 Quarter sheet cake = 9 x 12 x 2 inches or 9 x 13 x 2 I listed both to point something out to you. A quarter sheet cake is called a quarter because it takes four of them to equal a full sheet cake. Bakeries bake the full sheet cake in one pan in a commercial size oven.