Cake Serving Calculator
Estimate how many people a cake feeds from its shape, size, and tiers. Choose a party or wedding portion — both editable — and add tiers to total a whole cake at once.
Portion sizes vary by tradition and how the cake is cut — adjust to match your own serving chart or slice size.
Formula & how it works
Servings for a tier are its top area ÷ one portion's area. Top area is π × (diameter ÷ 2)² for round, side² for square, and length × width for rectangular. Portion area is portion width × portion length.
Each tier is calculated on its own and the totals are added, then rounded to whole servings.
Worked example
A single 8-inch round cake has a top area of about 50 square inches. Cut into 1 × 2 inch wedding slices (2 square inches each) that is roughly 25 servings; at 2 × 2 inch party slices (4 square inches) it drops to about 13. Stack a 6-inch round on top and the wedding total rises to around 39.
Reading the numbers
Portion size decides everything
The same cake can serve wildly different numbers depending on the slice. Formal wedding portions are tall, thin fingers of cake, so a tier stretches far; casual party slices are chunkier and fewer. Because there is no single standard, the presets here are only a starting point — set the portion to the slice you actually plan to cut.
Round cakes are the fuzziest
Area ÷ portion works neatly for square and rectangular cakes because they are cut on a grid. Round cakes are usually cut in concentric rings or wedges, so real charts vary from the pure area estimate. If you are catering a big event, lean toward the conservative side and round down.
Tiers add up, height does not
Servings come from the top area of each tier, so adding tiers adds servings, but a taller cake of the same footprint does not serve more people — it just makes taller slices. This tool assumes standard-height tiers; if yours are unusually short or tall, adjust the portion length to match the slice you will cut.