In the United States, the average height of a 13-year-old boy is 61.5 inches, while the average height of a 13-year-old girl is 62 inches. Average heights vary between 13-year-old girls and boys due in part to the fact that puberty often begins earlier in girls than in boys.
Although the aforementioned measures are considered average, it is normal for both boys and girls to have a wide height range. The 50th percentile on a sliding percentile scale relates to average height for both genders. Regularly, boys and girls are positioned at the extreme ends of the scale yet are nonetheless deemed healthy. Because every adolescent is unique, it is preferable to address any concerns with the child’s primary care physician.