One box of cake mix makes between 24 and 30 regular-size cupcakes when each cup is filled with 1/3 cup of batter, according to Betty Crocker. A regular-size cupcake is about 2 1/2 inches in diameter.
A cake mix makes about 64 mini cupcakes that are 1 3/4 inches in diameter. The mix generates up to 16 jumbo cupcakes that are 3 1/2 inches in diameter. A measuring cup or ice cream scoop helps keep the amount of batter consistent for each cupcake. Each cupcake must be no more than three-quarters full before baking. Tins that are too full often overflow during baking.