What is a Half Sheet Cake?

A half sheet cake is half of a sheet cake. They are rectangular in shape and can be decorated and served with ease. 

My name is Angie, I’m a dessert enthusiast and a self-taught baker who started a baking business from home. I know all about baking and cake decorating and I enjoy simplifying this process, making it more accessible to all! 

In this article, I will explain what a half sheet cake is, the sizes and dimensions of a half sheet cake, how to decorate one, and answer any further questions you may have. 

Keep reading to learn more!

What is a Sheet Cake?

A sheet cake is a cake that is baked in a rectangular, flat sheet cake pan. Sheet cakes are also known as “slab cakes” to some. They can be served with frosting on top or layered with a filling and then frosted. 

What is a Half Sheet Cake?

As the name suggests, a half-sheet cake is simply half of a full-sheet cake. You can make a half-sheet cake using a half-sheet cake pan or cut a full-sheet cake in half to get two half-sheet cakes. 

Half Sheet Cake: Benefits

Sheet cakes are a crowd favorite, perfect for gatherings with a lot of people as they are much easier to cut and portion out. The flat top gives you lots of room to decorate and customize with words. 

Half-sheet cakes are relatively effortless to make, making them one of the more affordable cake options for larger crowds. 

Half Sheet Cake: Pan Sizes & Dimensions

Depending on the manufacturer of your cake pan, the size of your half-sheet cake can vary slightly. Half-sheet cake pans usually measure 18” x 12”. Half-sheet cakes sold at most bakeries and grocery stores measure 15” x 11” with an average height of 2”, give and take an inch. 

How you decide to decorate your cake also plays a role in determining how big your final cake will be. Some like to trim off the edges of the cake making it smaller, while others like to apply a thick layer of frosting which would make the cake slightly larger. 

How Many People Can a Half Sheet Cake Serve

Typically speaking, a single-layer half-sheet cake can serve up to 40 people. Of course, the bigger each individual slice means the fewer pieces you will yield. 

A sheet cake slice can range from 1” x 2”, 2” × 2” to 2” × 3”. They will serve 36, 54, or 108 servings respectively.  

How to Decorate a Half Sheet Cake

Half-sheet cakes are most commonly decorated with buttercream frosting or ganache. Given its flat surface, you can easily achieve a smooth-frosted look by spreading your frosting evenly on all five sides of the cake, though I personally prefer a more textured rustic look.

After you’ve covered up all sides of the cake, you can use the remaining frosting to give your cake a nice border. You can do so by piping along the edges of the cake using your choice of a piping tip. I suggest a 1M star tip or a 6B french star tip. 

The border will act as a nice frame for any writing or edible printed picture you want to put on the cake. If a bordered look isn’t your cup of tea, another easy way to decorate your half sheet cake is to pipe rosettes all over it. This is a super easy way to give your homemade cake that professional look. 

As with any cake, you’d always want to present it on a cake board. I always recommend using a waxed, grease-resistant board to prevent your cake from sliding. 

Make sure to size up a little when choosing your box and your board to prevent damaging your cake. Trust me, you do not want all that hard work you put into piping the borders and frosting to go to waste. Go for something that is around 19″ x 14″ x 4″.  

How to Make a Half Sheet Cake: Recipes

While you can find sheet cake recipes on the internet, you don’t get a great variety of selections. 

But fear not! All you need to look for is any layer cake recipe that yields 16 cups of batter, which would be the equivalent of three 10” round cake layers. You can refer to this guide if you need more help with conversion.

The following are two recipes that you can use to make a half-sheet cake:

How to Store a Half-Sheet Cake

You can store an unfrosted half-sheet cake by wrapping it tightly in plastic wrap and freezing it. A frosted half-sheet cake (decorated without fresh ingredients) can stay at room temperature for up to four days, just make sure to cover it in a bowl or packaging that will prevent dust or any other particles from reaching it. 

If you are to freeze a frosted half-sheet cake, leave it in the fridge for 15 minutes before wrapping it and putting it in the freezer. This will help the frosting harden and not get easily damaged by the wrapping process. 

Wrapping the cake, freezing it, or leaving it out at room temperature all prevent the cake from drying out. A frozen sheet cake can last in the freezer for up to one year. You can store your cake in the refrigerator as well but it will be at risk of drying out.  


Below are some common questions related to half-sheet cakes.

How many boxes of cake mix do I need for a half-sheet cake?

You need three boxes of cake mix to make a single-layer half-sheet cake.

What’s the difference between half-sheet cake, quarter-sheet cake, and full-sheet cake?

Sheet cakes are available in various sizes. A full sheet cake typically measures 18” x 24”, serving up to 117. A half sheet cake measures 13” x 18”, serving around 54, and a quarter sheet cake measures 9” x 12”, serving around 18 people. 

How do you cut a half-sheet cake?

Always cut with a long and thin knife, preferably plain and not serrated. Determine how many people you are serving before cutting into your cake according to our guide above. I recommend scoring your cake to make sure you cut enough pieces for everybody. 

Have a clean hot towel on the side and wipe down your knife after each cut to get a neat and clean cut. 

How many does a half-sheet cake serve?

A half-sheet cake can serve 108, 54, or 36 depending on the size of the slices and the number of layers. 

How much is a half-sheet cake?

Half-sheet cakes are sold in supermarkets and bakeries. Depending on how upscale the vendor is, prices will vary. You can get a half-sheet cake for $20 at Costco or $30 at Walmart.  

Final Words

Bringing a half-sheet cake will easily make you everyone’s favorite person at any gathering. They are tasty, very easy to make, and don’t require much time at all. 

Calculations can be slightly annoying at first but once you get the hang of it, I’m sure you’ll be baking sheet cakes all the time. 

If you have any more questions regarding half-sheet cakes, let me know in the comments and I’ll get back to you as soon as I can!

About Angie
I am a self-taught baker. I’ve been baking for over 10 years and started my own home baking business as a side hustle. I was born in Hong Kong and spent a pretty big chunk of my life in Canada. If you’re ever looking for me, I am probably there whisking vigorously away in the kitchen.

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  • Maurisabel

    For wedding cake how many serving does half a sheet serve

    • Michelle

      Hi Maurisabel,
      That depends on the size of your slices. Small slices can render up to 108 slices.

  • Michael Neely

    I often shop at Walmart, people ask me why I’ve been with this place for so long and why there are discount codes for my purchases on the DazzDeals website, all of which are free to use.

    • Michelle`

      Thanks for sharing, Michael!
      Happy baking,

  • Sandy

    We will be traveling from Denver Colorado to Moab Utah with the full sheet wedding cake. So yo you have any ideas how to do this ? Thank you