Adolescence is a time of profound physical change, often sparking curiosity about typical development. Height is one of the most noticeable markers of this maturation process, and the rate at which a teenage girl grows is highly variable. Understanding the typical measurements and the biological mechanisms of adolescent growth can provide clarity. This period of rapid physical development is governed by a complex interplay of inherited traits and hormonal signals.
Understanding the Average Measurements
The concept of an “average” height is best understood through the 50th percentile data collected by health organizations. This percentile represents the midpoint, meaning half of the girls in that age group are taller and half are shorter. For a 13-year-old girl, the average height falls between approximately 61.7 and 62.3 inches (156.7 to 158.3 centimeters). By age 16, the average measurement increases to about 64.0 to 64.1 inches (162.5 to 162.7 centimeters), showing a deceleration in growth. The final measurement is reached around age 18, where the average height is approximately 64.2 inches (163.0 to 163.1 centimeters).
The Timing of the Puberty Growth Spurt
Adolescent linear growth occurs through a period of acceleration known as the pubertal growth spurt, which generally begins earlier for girls than for boys. This growth phase typically initiates between the ages of 8 and 13. The fastest rate of vertical growth, termed Peak Height Velocity (PHV), generally occurs around 11.5 to 12 years of age. During PHV, a girl may grow at a rate of nearly 3.8 inches (9.8 centimeters) in a single year. This period of maximum growth is closely tied to other markers of sexual maturation, usually beginning roughly a year after the start of breast development. The growth spurt usually concludes before the onset of menarche, which signals that the body has completed the majority of its vertical growth.
Primary Factors Determining Height
A person’s final adult height is a result of both inherited traits and environmental influences working together. Scientists estimate that inherited DNA accounts for approximately 80% of an individual’s height. Hundreds of gene variants contribute to this complex trait, meaning that height is not determined by a single gene. The heights of the biological parents offer a strong estimation of the likely adult height, often calculated using a formula that averages the parents’ heights and adjusts for the child’s sex. The remaining percentage of height is influenced by environmental factors that determine whether a girl reaches her full genetic potential. Adequate nutrition provides the necessary building blocks for bone growth, with sufficient intake of protein and minerals like calcium being important. Sleep habits also play a biological role in height development, as the majority of the Human Growth Hormone (hGH) is released in pulses during periods of deep sleep.
When Does Vertical Growth End?
The definitive end of vertical growth is a biological process called epiphyseal fusion, or the closing of the growth plates. Growth plates are areas of cartilage located near the ends of the long bones in the arms and legs. Growth occurs as new cartilage is produced and then converted into bone tissue. The sex hormone estrogen plays a dual role in this process, first contributing to the pubertal growth spurt and then initiating the closure of the growth plates. High levels of estrogen cause the cartilage cells to age rapidly, leading to the abrupt fusion of the growth plate with the rest of the bone. Once this fusion is complete, no further longitudinal bone growth is possible. For most girls, final adult height is typically achieved by age 14 or 15.