Most girls hit their growth spurt around age 10, about two years earlier than boys. The spurt typically peaks at age 12 and winds down by about 14 or 15, though the exact timing varies from girl to girl. Understanding what triggers the spurt, what signs come first, and how much growing is left afterward can help you make sense of what’s happening.
When the Growth Spurt Starts and Peaks
The pubertal growth spurt in girls begins around age 10 on average and reaches its fastest rate, called peak height velocity, about two years later at age 12. By roughly age 14 to 15, the spurt has run its course and height gains slow dramatically. For comparison, boys don’t start their spurt until about 12 and don’t peak until around 14, which is why girls are often taller than their male classmates for a year or two in middle school.
During the fastest phase, girls can grow 3 to 3.5 inches per year. Before puberty, the baseline rate is closer to 2 inches a year, so the jump is noticeable. The entire spurt, from start to finish, lasts about four to five years.
Early Signs That a Growth Spurt Is Coming
The growth spurt doesn’t happen out of nowhere. A few physical changes reliably signal that it’s on the way. The earliest sign in most girls is breast budding: small, nickel-sized bumps under the nipple. In about 15% of girls, pubic hair appears before breast budding, but for the majority, breast development comes first. The fastest height growth happens between the start of breast budding and about six months before the first period.
You might also notice that feet grow before the rest of the body catches up. Shoes that fit three months ago suddenly feel tight, and that’s often the first practical clue parents spot. A small amount of clear or white vaginal discharge can also appear six to twelve months before a girl’s first period, which itself is a late-stage event in the growth timeline.
How the First Period Fits In
A common question is whether girls keep growing after their first period. The answer is yes, but not by much. Peak height velocity occurs six to twelve months before the first period arrives, so by the time menstruation starts, the fastest growing is already behind her.
After the first period, the average girl grows about 3 inches (7 cm) more. That number isn’t fixed, though. Girls who get their period on the early side, around age 10, tend to grow about 4 inches afterward. Girls whose period arrives later, around age 15, typically add only about 2 inches. The earlier the period, the more residual growth remains, because the growth plates haven’t had as much time to close.
What Drives the Spurt
The growth spurt is powered by a combination of hormones working together. Rising levels of estrogen and growth hormone are the main drivers, but they don’t act alone. Androstenedione, a mild androgen produced by the adrenal glands and ovaries, also contributes. Height velocity during the spurt correlates with levels of all three: estrogen, growth hormone, and androstenedione. Estrogen in particular plays a dual role. In smaller amounts it stimulates growth, but at higher concentrations it’s also responsible for signaling the growth plates to eventually close, which is why growth slows and stops after the spurt peaks.
When Growth Plates Close
Height growth ends when the growth plates at the ends of the long bones fully fuse. In girls, this happens roughly two years earlier than in boys. By age 17, about 75% to 98% of growth plates across different bones have completely fused in girls. Some girls reach their final adult height by 14 or 15, while others add small amounts through 16 or 17. After full fusion, no further height gain is possible regardless of nutrition, exercise, or supplements.
What Counts as Early or Late
Puberty starting anywhere between age 8 and 13 in girls falls within the normal range. That’s a wide window, which means two perfectly healthy girls can start their growth spurts four or five years apart. A girl who begins developing at 8 will likely hit her peak growth by 10, while a girl who starts at 13 may not peak until 15.
Signs of puberty before age 8, such as breast development or menstruation, are considered precocious puberty and are worth discussing with a pediatrician. On the other end, if a girl has no breast development by age 13, or has started developing breasts but hasn’t gotten her period by 15, that’s considered delayed puberty. Both situations can have underlying causes that a specialist can evaluate, though in many cases the timing is simply a family trait.
Factors That Influence Timing
Genetics is the strongest predictor. If a girl’s mother hit her growth spurt early, there’s a good chance her daughter will too. But environment plays a role as well. Adequate nutrition, particularly sufficient calories and protein during childhood, supports normal pubertal timing. Chronic undernourishment can delay puberty, while higher body fat levels are associated with earlier onset. Girls who are very physically active, such as competitive gymnasts or distance runners, sometimes experience a later start to puberty, though this isn’t universal.
Chronic health conditions like celiac disease, inflammatory bowel disease, or thyroid disorders can also shift the timeline. If growth seems to have stalled or puberty appears unusually early or late, a pediatrician can track growth velocity on a chart over time. A single height measurement is less useful than the pattern across multiple visits, which reveals whether a girl is accelerating, decelerating, or holding steady on her growth curve.