What are the dimensions of an average birthday cake?

There's no single "average" birthday cake size, as it depends on the number of people you're serving! Here's a breakdown of common sizes and the approximate number of servings they offer:

* 6-inch round: 6-8 servings

* 8-inch round: 10-12 servings

* 9-inch round: 12-15 servings

* 10-inch round: 15-20 servings

* 12-inch round: 20-25 servings

* 14-inch round: 25-30 servings

Other factors influencing cake size:

* Cake layers: A single layer cake serves fewer than a multi-layered cake.

* Cake shape: Square or rectangular cakes can serve more people than round cakes of the same dimensions.

* Individual serving size: People eat different amounts!

If you're unsure, it's always best to overestimate the number of servings you'll need!