Most girls stop growing in height around age 14 to 16, though small amounts of growth can continue into the late teens. The timeline depends largely on when puberty starts, because height gain is closely tied to the hormonal changes that drive development. A girl who starts puberty earlier will generally stop growing earlier, while a late bloomer may keep growing longer.
The Growth Spurt and When It Peaks
Girls experience their fastest growth during the early stages of puberty, typically between the time breast development begins and the arrival of their first period. The average age for peak height velocity in girls is about 12.1 years, though this varies by a year or more in either direction. During this peak, girls commonly grow 8 to 12 cm (roughly 3 to 5 inches) per year.
This rapid phase doesn’t last long. By the time a girl gets her first period, the fastest growth is already behind her. What remains is a slower, tapering phase that adds the final inches.
How Much Height Comes After a First Period
A common question parents and teens have is how much taller a girl will get after her period starts. On average, girls grow about 7 cm (3 inches) after their first menstrual period, but the exact amount depends on how old they were when it arrived.
Data from the Fels Longitudinal Study, one of the longest-running growth studies in the U.S., shows a clear pattern. Girls who start menstruating at age 10 gain about 10 cm (4 inches) afterward, while those who don’t get their period until age 15 gain only about 5 cm (2 inches). This makes sense: earlier puberty means more remaining growth potential at the time of the first period, even though the total growing window ends up being shorter.
Most of this post-period growth happens within the first one to two years. Research using detailed growth models shows that pubertal growth extends roughly 1.6 years past the first period in its active phase, though the very last traces of growth (reaching 99% of adult height) can stretch out to about 3.2 years after.
What Happens Inside the Bones
Height growth comes from growth plates, which are bands of cartilage near the ends of the long bones in your legs, arms, and spine. During childhood and puberty, these plates produce new bone tissue, making bones longer. Eventually, rising estrogen levels cause the plates to harden and fuse shut permanently.
In girls, the earliest complete fusion of growth plates at the knee (one of the key sites for leg length) begins around age 16 to 17. However, full fusion of all knee bones in every individual isn’t seen until the 20 to 21 age group. This is why some girls notice very minor height changes into their late teens, even though the significant growth stopped years earlier. By the early twenties, the plates are fully closed and no further height gain is possible.
Early Puberty and Its Effect on Final Height
When puberty starts unusually early, a condition called precocious puberty, it can affect how tall a girl ends up. The early surge of estrogen speeds up bone maturation and shortens the total window for growth. A girl who develops very early may be the tallest in her class for a while, then end up shorter than expected as an adult because her growth plates close sooner.
That said, the impact on final height is often smaller than parents fear. Studies of girls with central precocious puberty show that untreated girls reached an average adult height of 163 cm (about 5’4″), while those who received treatment to pause puberty reached about 160 cm (about 5’3″). Both groups landed within a normal range. The real concern is when puberty begins before age 8, which is when pediatricians typically evaluate whether intervention makes sense.
Late Bloomers Catch Up
Some girls grow more slowly than their peers through childhood and enter puberty later than average. This is called constitutional growth delay, and it’s the most common reason a child gets referred to a specialist for short stature. About 15% of those referrals fall into this category, and it’s more common in boys, though girls experience it too.
The hallmark of constitutional delay is that a girl’s bone age (measured by an X-ray of the hand) lags behind her calendar age. She may look younger and shorter than classmates, but her body is simply running on a slower clock. Once puberty does kick in, these girls experience a normal growth spurt and typically reach a final height consistent with their family’s genetics. The prognosis is excellent: they catch up, and their growth follows the curve that matches their bone age.
What Determines Final Height
Genetics is the single biggest factor. Pediatricians use a simple formula to estimate a girl’s expected adult height: take the father’s height, subtract 5 inches (13 cm), add the mother’s height, and divide by 2. The result gives a midpoint, and most girls end up within about 2 inches above or below it.
Beyond genetics, several factors can nudge the outcome. Nutrition plays a significant role, particularly adequate protein, calcium, and vitamin D during the growing years. Chronic malnutrition or untreated conditions like celiac disease can suppress growth. Adequate sleep matters because growth hormone is released primarily during deep sleep. Girls who get consistent, sufficient sleep through puberty give their bodies the best opportunity to reach their genetic potential.
The timing of puberty itself also shapes the math. Girls who enter puberty later tend to have a slightly longer total growing period, which can translate into a taller final height. Those who enter puberty earlier have a shorter window but grow faster during it. In most cases, these differences balance out, and final height lands close to the genetic target regardless of timing.
A Quick Timeline
- Ages 8 to 13: Puberty typically begins, marked by breast development. Growth starts accelerating.
- Around age 12: Peak growth rate hits, averaging about 12.1 years. Girls may grow 3 to 5 inches this year.
- Ages 10 to 15: First period arrives (average age is 12.5). The fastest growth is already over.
- 1 to 3 years after first period: Growth slows significantly, adding a final 2 to 4 inches on average.
- Ages 14 to 16: Most girls reach their adult height. Growth plates begin fusing.
- By age 20 to 21: All growth plates are fully closed. No further height increase is possible.