Cake Servings Calculator

How it is calculated

The tool works out the top area of the round cake and divides it into portions of 25 cm² each (about a 5 × 5 cm slice): area = π × (d/2)², then servings = floor(area ÷ 25 × layers ÷ 2). d is the cake diameter in centimetres and layers is the number of stacked layers. A cake with 2 layers is the baseline, so one layer gives half as many servings and three layers give one and a half times as many. The result is rounded down to a whole number and is never below 1. There is only one portion size built in: no thinner wedding-style slice and no choice of square or sheet cakes, so for small dessert slices expect to cut more than the tool shows.

Common mistakes

• Entering the diameter in inches. The field is centimetres, so a 10-inch cake is about 25, not 10; typing 10 gives only 3 servings.
• Entering the radius or the side length of a square pan instead of the diameter of a round cake.
• Counting a single layer as the full count. One layer yields half what two layers do at the same diameter.
• Expecting wedding-size slices. The portion here is a fixed 25 cm², roughly a party slice, so thin wedding cuts will give more pieces than the tool says.
• Ignoring height. A tall tiered cake is cut differently, and the layer count is only a rough scaling, not a measure of the real slice size.