Cake Servings Calculator

How it works

A cake is cut into slices of a set footprint seen from above: Wilton's serving chart uses party slices of about 1½ × 2 in (3 sq in) and wedding slices of about 1 × 2 in (2 sq in), each the full height of the cake. The area estimate divides each tier's top area by the slice footprint, rounds down to whole slices, and adds the tiers.

Wilton's chart is based on cakes about 4 in tall (two 2-in layers) and says cakes 3 to 6 in tall give the same number of servings, while cakes shorter than 3 in give half. The calculator applies the same rule: under 3 in, each slice takes twice the top area. Cakes taller than 6 in are outside the guide and are not calculated.

Where every tier is a pan size in Wilton's chart, the chart's own figure is shown beside the area estimate. The two differ because the chart reflects how a cake is actually cut (round cakes in rings, with wedges at the centre), while the estimate assumes the whole top divides into equal slices.

For a guest count, the calculator reports the top area those guests need, the matching diameter or side, and the smallest single pan in Wilton's chart whose servings cover the guests.

Formula

slice footprint = 1.5 × 2 = 3 sq in (party) or 1 × 2 = 2 sq in (wedding)
height = layers × layer height;  under 3 in → footprint × 2;  over 6 in → not covered
round top = π × (d ÷ 2)²;  square top = s²;  sheet top = l × w
servings per tier = ⌊top ÷ footprint⌋;  total = sum over tiers
guest count: minimum top = guests × footprint;  round d = 2√(top ÷ π);  square s = √top

Example

A three-tier round cake of 6, 8 and 10 in tiers, each two 2-in layers (4 in tall), cut in wedding slices: the tops are 28.3, 50.3 and 78.5 sq in (157.1 sq in in all), which divide into 14 + 25 + 39 = 78 slices of 2 sq in. Wilton's chart gives 12 + 24 + 38 = 74 for the same pans.

For 50 wedding guests and a 4 in tall round cake, the top must be at least 50 × 2 = 100 sq in, a diameter of 11.3 in; the smallest single round pan in Wilton's chart that covers 50 is the 12 in round (56 wedding servings).

Assumptions and limitations

• Servings are a guide, not a guarantee; Wilton notes that serving size depends on who is cutting and that actual results may vary.
• The area estimate assumes the whole top divides into equal slices with no waste. For round cakes, rings and centre wedges make the real count differ: an 8 in round gives 25 wedding slices by area against 24 in Wilton's chart, and 16 party slices by area against 20 in the chart.
• Slice footprints and the 3 to 6 in height rule are from Wilton, "Ultimate Cake Serving Chart: Our Ultimate Guide to Perfect Portions" (posted 29 October 2025). The chart figures shown are its 4 in high (two-layer) rows for round, square and sheet pans.
• Height is layers × layer height; filling and frosting thickness are not counted. Cakes under 3 in tall are halved as Wilton describes, and the chart figure is halved and rounded down.
• The smallest chart pan considers single pans only; a guest count above the largest pan needs tiers or more than one cake, which this question does not size.

Frequently asked questions