Tip - What Are Half Sheet Cake Sizes? | eHow

A half sheet cake, or 1/2 sheet cake, is a large rectangular-shaped cake that is normally served at a party or any time a crowd is expected. Because of the difference in available pan sizes, half sheet cakes come in a variety of sizes. A half sheet cake from a bakery is often larger, and serves more people, than a typical sheet cake baked at home.