Food
Cake Serving Calculator
Enter cake diameter (or length × width) and portion style to estimate servings.
How many servings from a cake?
Cake servings are estimated from surface area divided by a portion footprint. For rounds, area = π × (diameter ÷ 2)²; for sheets, enter length × width instead (when both are set, the sheet wins). Party portions use a smaller footprint (~4 × 5 cm) than dessert slices (~5 × 7 cm), so the same tin yields more party servings. Tall celebration cakes cut into slender wedges can stretch further than a short sponge — treat the count as a planning guide and confirm with your baker’s chart. Icing style, filling and guest appetite still move the real number. For tin size swaps see cake tin conversion; for cupcake counts use cupcake quantity.
Worked example
20 cm round → area ≈ 314 cm². Party portions (~4 × 5 cm) ≈ 15 servings; dessert portions (~5 × 7 cm) ≈ 8 servings.
Limits and assumptions
Indicative portion areas only. Height, dense fillings and baker’s charts vary — not a catering guarantee.
Frequently asked questions
When do I use diameter versus length and width?
Enter diameter for round tins. For rectangular sheets, enter length and width (both greater than zero) and the sheet area is used.
Are wedding portions smaller?
Often yes — many couples treat them like party-style or even smaller cuts. Adjust expectations downward if needed.
What if we serve cupcakes instead?
Count one cupcake per guest (or use the cupcake quantity tool); this page is for cut cakes.
How do multi-tier cakes work?
Estimate each tier’s servings from its diameter, then add the tiers together.