Are you wondring of the proper measurements for your custom cereal box? So, we’re here to assist you with that. We will provide you with all the information you require regarding std cereal box dimensions and how to make the ideal size of a cereal box. So let’s start with how tall is a box of cereal. Buy Honey Nut Cheerios Gluten Free Breakfast Cereal Giant Size (27.2 oz.) from Claws Custom Boxes.