A round cake 10 inches in diameter feeds approximately 35 people and a 10-inch square cake is appropriate for 45 people, while a 10-inch heart-shaped cake only feeds 30 people. This assumes that the cake is cut so that slices are 4 inches in height, 2 inches in length and 1 inch in width.
The ingredients and density of the cake also influence how many people it can serve. For example, cakes made out of dense fruit will serve more people than a standard flour cake of the same size. When selecting a cake size, it is also important to allow for a few extra servings. Some people may not be satisfied with the traditional size of a cake slice, and others may decide to attend at the last minute.