The Cake Size Chart is for a size reference, all cake serving size in the chart are based on a 1 x 2 inches cake slice size.
This size chart is based on a 6 inch high cake, each tier has 3 layers of cake not including frosting and filling. Meaning each tier yields 3x2” layers of cake.
For a Tall Cake such as a double barrel the serving size is two cakes that are stack together to achieve the height.
Please plan according your party size need.