🎂 Understanding Cake Sizes (It’s Like Ordering Pizza!) 🍕 Cake sizes are listed in inches (or centimeters) in the US — for example, 6-inch, 8-inch, 9-inch, or 9"x13" That number refers to the size of the pan the cake was baked in — specifically, its diameter (or length and width, for sheet cakes). 👉 So: An 8-inch cake is 8 inches across. A 9-inch cake is 9 inches across. Both are the same height once baked and frosted — the only difference is the diameter (and how many servings you’ll get). Th