1. Development rules of height and weight of three-year-old babies Three years old is a critical period for children’s growth and development. At this time, the growth rate of height and weight will gradually slow down. Generally speaking, the height of a three-year-old boy is about 95-105 cm and the weight is about 14-18 kg; while the height of a three-year-old girl is about 93-103 cm and the weight is about 13-17 kg. Of course, this is only a general range, and each child\’s growth and development is different. 2. How to promote the healthy development of the height and weight of a three-year-old baby 1. Reasonable diet: A three-year-old baby needs to eat enough nutrients