The standard height of a 12-year-old girl is usually around 154cm, but there are individual differences. According to China’s standard pediatric height formula for children aged 2 to 12, the standard height of a 12-year-old girl is about 154cm. But the height of girls is related to many factors, such as genetic factors, environment, nutritional status and so on. So there are individual differences. Genetic factors account for about seventy percent of the height, if the parents’ height is high, the child’s height is relatively high; in addition to genetic factors, nutritional status is also very important, to consume more protein-rich foods, balanced diet, to provide children with the nutrients needed for growth and development. In addition, it is also important to have a good living environment, the need for adequate sleep, to ensure the regular secretion of growth hormone, and then sports exercise, appropriate bouncing exercise can help children height growth. If the height of a 12-year-old girl is obviously different from that of a child of the same age, it is recommended to seek medical attention in time.