Chex brand cereal has downsized from a 12.8-ounce to 12-ounce box, so you will want to purchase two boxes if using this brand. Add 1-2 cups extra rice chex cereal if using a 12-ounce box and use the remainder for cereal or a different recipe. I used the 12.8-ounce Aldi brand version of rice Chex, and it worked perfectly. Plus, the Aldi brand is much cheaper! :)