147 cm is considered normal for a 12 and a half year old boy. According to the 2018 height development grade evaluation of children and adolescents aged 7 to 18 years old, the height range of 12-year-old boys is between 134.48 and 169.89 centimeters, and the height range of 13-year-old boys is between 143.01 and 177.38 centimeters, and the height of 147 centimeters is also within the normal range, so it is considered normal and does not need special treatment. The relationship between height and heredity is relatively close, generally the parents are taller, the child’s stature will also be taller, if the parents are shorter, the child’s stature will generally be shorter, as long as the height is in the normal range, generally do not need to worry too much. Height is not only related to heredity, but also related to some other factors, such as nutrition, exercise, and sleep, emotions and so on, so it should be in the life of attention. Twelve and a half years old boy has begun to enter puberty, the growth rate is relatively fast, should be balanced nutrition, moderate outdoor exercise, especially to do some jumping sports, should ensure adequate sleep, to avoid too much mental stress.