Most girls reach their full adult height between ages 13 and 15, though some continue growing until 16 or even into their late teens. The timeline depends heavily on when puberty starts, since the growth spurt and its wind-down follow a predictable sequence tied to pubertal development rather than a fixed calendar age.
The Growth Spurt Timeline
Girls go through their fastest growth during the middle stages of puberty, typically between ages 9 and 14. During this peak period, they can grow more than 3 inches per year, with average peak height velocity clocking in at about 3.9 inches (9.8 cm) per year. For most girls, roughly 69%, this fastest growth happens around Tanner stage 3, which is the midpoint of puberty.
Before and after that peak, growth still happens but at a slower pace of about 2.75 inches per year. Once a girl passes through her peak growth spurt, height gain decelerates steadily. Most girls reach their full height by age 16, but a small number continue adding fractions of an inch through age 20.
How Your First Period Fits In
A girl’s first period (menarche) is one of the most practical markers for estimating how much growth is left. On average, girls grow about 3 inches (8 cm) after their first period. But that average masks enormous variation. A large study published in Frontiers in Pediatrics found postmenarcheal growth ranged from virtually nothing (less than a tenth of an inch) to over 12 inches, depending on how early in puberty the period arrived.
Girls who get their period on the earlier side of puberty tend to have more growing left to do. Those who start menstruating later, when puberty is already well advanced, may gain very little height afterward. So the old rule of thumb that “you’ll grow two more inches after your period” is a rough guideline at best.
What Actually Stops Growth
Height comes from long bones like the femur and tibia, which grow from zones of cartilage near each end called growth plates. Throughout childhood and puberty, these plates continuously produce new bone tissue, lengthening the skeleton. Estrogen plays a dual role in this process: at low levels during early puberty, it triggers the growth spurt. But as estrogen rises to higher concentrations in late puberty, it causes those cartilage growth plates to harden into solid bone, permanently closing them and ending height gain.
Once growth plates fuse, no amount of nutrition, exercise, or supplementation can add more height. This fusion is gradual and doesn’t happen in every bone at the same time, which is why the last bits of growth can trickle in over a year or two after the major spurt is over.
Genetics and Other Factors
About 80% of your final height is determined by genetics. The remaining 20% comes from environmental factors, particularly nutrition, overall health during childhood, and conditions during pregnancy. A child who is well-nourished, active, and healthy will generally reach the taller end of their genetic potential, while chronic illness, poor diet, or food insecurity can limit final height.
Prenatal factors matter too. A mother’s nutrition during pregnancy, smoking status, and exposure to environmental toxins can all influence a child’s growth trajectory years later. Sleep also plays an indirect role, since growth hormone is released primarily during deep sleep.
When Puberty Starts Early
Girls who enter puberty unusually early (before age 8, a condition called precocious puberty) often end up shorter as adults than expected. The mechanism is straightforward: early estrogen exposure triggers the growth spurt sooner but also closes growth plates sooner, cutting the total growing period short. These girls may be tall for their age at first, then stop growing while their peers keep going.
Treatment for precocious puberty works by temporarily pausing puberty’s hormonal signals, which slows bone maturation and extends the window for growth. The goal is to let the skeleton catch up to where it would have been with normal timing. Results tend to be best when treatment continues until bone age reaches about 12 to 12.5 years, though the decision is individualized.
Predicting Final Height
Pediatricians have several tools for estimating how tall a girl will eventually be. The simplest is the mid-parental height method: add both parents’ heights together, subtract 5 inches, and divide by two. This gives a rough target, but individual variation is wide.
More precise methods, like the Khamis-Roche formula, use a girl’s current age, height, weight, and her parents’ heights to generate a prediction. Even this approach, though, is only accurate to within about 2.7 inches in either direction 95% of the time. Methods that include a bone age X-ray (which shows how mature the growth plates are) tend to be more accurate, since they directly measure how much growing capacity remains rather than estimating it from age alone.
If a girl’s growth seems to have stalled unusually early or she’s significantly shorter than expected based on her family, a bone age X-ray can clarify whether her growth plates are still open and how much potential height remains.