Costco Cake Servings: How Many People Can One Sheet Cake Feed?

If you’ve ever walked into a Costco bakery and seen those huge sheet cakes, you probably wondered how many guests a single cake can serve. The answer depends on the cake’s dimensions, the type of celebration, and how you cut the pieces. In this guide we’ll break down the numbers, show you the best way to slice the cake, and give you a few ordering tricks so you never run out of frosting.

What Size Is a Typical Costco Sheet Cake?

Costco usually offers two main sheet cake sizes: the 9‑inch by 13‑inch “full sheet” and the 5‑inch by 10‑inch “half sheet”. The full sheet is the one most people remember from birthday parties and office gatherings. It weighs about 12 to 14 pounds and is covered in a smooth layer of buttercream. The half sheet is lighter, about 5 to 6 pounds, and works well for smaller groups.

Knowing the size is the first step to estimating servings. The general rule of thumb is that a full sheet yields about 96 standard slices, while a half sheet provides roughly 48 slices. Those numbers assume a classic 2‑inch by 2‑inch piece, which works for most birthday cakes and casual parties.

How to Cut the Cake for Different Crowd Sizes

Not every event needs 2‑inch squares. If you’re feeding a group of adults who want a richer bite, cut 2‑inch squares. For kids or a mixed crowd, try 1.5‑inch squares to stretch the cake further. You can also cut rectangular strips – a 1‑inch by 3‑inch piece feels like a bite while still giving you about 120 pieces from a full sheet.

Here’s a quick cheat sheet:

• Full sheet, 2‑inch squares: 96 servings – perfect for 80‑100 guests with a few extras.
• Full sheet, 1.5‑inch squares: 144 servings – ideal for large family reunions.
• Half sheet, 2‑inch squares: 48 servings – good for a small office party.
• Half sheet, 1.5‑inch squares: 72 servings – works for a birthday with 60 kids.

Adjust the cut size based on the number of guests and how much other food you’re serving. If you have a full buffet, smaller pieces will keep the cake from disappearing too fast.

Ordering the Right Cake for Your Event

When you call Costco, tell them the number of guests and the type of event. The staff can recommend whether a full or half sheet is the best fit. If you need a custom design, order at least three days in advance – Costco often needs that time to bake and decorate the cake.

Don’t forget to ask about frosting options. While buttercream is the default, you can request a chocolate ganache or cream cheese frosting for an extra flavor boost. Those upgrades usually add a small fee, but they can make the cake feel more special.

One last tip: ask for a cake board if you’re buying a full sheet. It makes transport easier and gives you a stable surface for cutting.

With these numbers in mind, you can confidently order a Costco cake that feeds everyone without waste. Whether you’re planning a birthday, a graduation, or just a weekend get‑together, the right slice size and a quick call to the bakery will keep your dessert game on point.