A full sheet cake is 18 inches by 24 inches and serves approximately 80 people. A full sheet cake can be cut into 64 2-inch-by-3-inch slices or 96 2-inch-by-2-inch pieces. Other popular sheet cake sizes are half- and quarter-sheet cakes.
A half-sheet cake is typically baked in a 12-inch-by-16-inch pan, but may also be made in a 11-inch-by-15-inch pan. A half sheet typically feeds 40 people. It can be sliced into 32 2-inch-by-3-inch slices or 48 2-inch-by-2-inch pieces.
A quarter-sheet cake is 9 inches by 13 inches, the size of a typical home cake pan. A quarter-sheet cake serves approximately 20 people. It can be sliced into 16 2-inch-by-3-inch slices or 24 2-inch-by-2-inch pieces.
Half- and full-sized sheet cakes are often baked in two layers with filling added. To bake a half- or full sheet cake in a smaller oven, two or four quarter-sheet cakes can be baked and placed together before frosting as one large cake. This segmented method adds the bonus of making a cake that looks like one large cake but can contain a variety of cake and filling flavors, such as vanilla cake, chocolate cake, lemon cake and yellow cake in each of the four quarters.