Small Cake From Half of a Box of Cake Mix

Small Cake From Half of a Box of Cake Mix

The Spruce / Julia Estrada

Prep: 10 mins
Cook: 30 mins
Total: 40 mins
Servings: 4 servings

Sometimes you don't need a whole box of cake mix. You can use half of the box of cake mix to make a smaller cake and save the rest for another time.

Cake mixes typically come in 15.25- to 18-ounce boxes. This is enough mix for two 8-inch or 9-inch rounds for a layer cake, a 13-by-9-inch sheet cake, or 24 cupcakes. That can be too much cake if you have a small family. You won't want to waste a full-size cake (or stuff yourselves trying to eat it all). You may only need to make a small cake for another recipe, such as a trifle or cake pops, or you might only want half of a batch of cupcakes.

You can customize this recipe by stirring in a small amount of other ingredients—about half a cup. You could add some chocolate chips, nuts, dried cherries or cranberries, sprinkles, or anything else you'd like.

Be sure to read the instructions on the box if you are using a fancier type of cake mix that already has add-ins or requires extra ingredients. It is usually safe to just use half of the amounts listed.


  • 1 3/4 cups cake mix (half of a 15.25 to 18-ounce box)
  • 2/3 cup water
  • 1/4 cup oil
  • 1 egg

Steps to Make It

  1. Gather the ingredients.

    Small Cake From Half of a Box of Cake Mix ingredients

    The Spruce / Julia Estrada

  2. Preheat the oven to 350 F. Spray an 8-inch square or round cake pan with a nonstick baking spray containing flour.

    greased cake pan

    The Spruce / Julia Estrada

  3. In a medium bowl, combine the cake mix, water, oil, and egg. Mix until combined, then beat for 1 minute at medium speed.

    combine the cake mix, water, oil, and egg

    The Spruce / Julia Estrada

  4. Pour the cake batter into the prepared pan.

    cake batter into the prepared pan

    The Spruce / Julia Estrada

  5. Bake for 25 to 35 minutes or until a toothpick inserted into the center of the cake comes out clean. The cake should also be pulling away from the sides of the pan.

    Small Cake From Half of a Box of Cake Mix in a baking pan

    The Spruce / Julia Estrada

  6. Let the cake cool completely on a wire rack, then frost or dust with powdered sugar.

    Small Cake From Half of a Box of Cake Mix with powdered sugar on top on a cooling rack

    The Spruce / Julia Estrada


  • The results can vary for different types of cake mix, so check the finished cake to see how it turns out. The baking time will vary depending on your oven—this is always something that requires checking for doneness rather than relying on a timer. You might want to adjust the amount of water, milk, or oil added next time you use the half box of cake mix.
  • The unused (dry) cake mix should be kept in a sealed ziplock plastic bag to keep it fresh until you are able to use it. It is wise to mark a date on the box indicating when it was opened. Try to use the remaining cake mix within a couple of weeks. Even the small amount of air let into the packaging can start degrading the ingredients. This can result in the cake not rising as much. If you see any evidence of mold or discoloration, discard the unused cake mix rather than using it.

Recipe Variation

  • For some cake mixes, it can work to substitute milk or fruit juice for the water.