my son is 3 years old...his height is 88.1cm. is this average height for his age?

A. he is slightly less in height... but don't worry too much... he will grow by his own.. most of the baby grow up in height in their teenage.. If you want you can encourage him to increase his height when he is in his childhood .. Engage him in sports activities like swimming, basketball, skipping, stretching, etc in his teenage... Also include milk and dairy products, tofu, soyabean, carrot, spinach, peas, pumpkin, cabbage, green beans, banana, grape, papaya, water melon, mango, oats, nuts, flax seed, pumpkin seeds, etc in his diet so don't worry too much... please consult the pediatrician regarding the vitamin D defficiency.. sometimes vitamin D defficiency leads to less height growth too..