Four-inch cakes are generally suitable for 2-4 people. Specifically, if you enjoy it alone, you can choose 1 pound (about 454 grams) cake; If two people share, you can choose 2 pounds (about 900 grams) of cake; If four adults or four children share it together, you can choose a cake of 3 kg (about 1350 g).
In addition, if people eat less or want more exquisite cakes, they can choose a four-inch cake with a diameter of 10 cm. If the eater has a big appetite or wants more cakes, you can choose a four-inch cake with a diameter of 15cm.
In short, there is no fixed standard between the size of a four-inch cake and the number of people who eat it, and it can be chosen according to personal needs and actual conditions.