Growth plates close between ages 13 and 20 for most people, with girls finishing about two years earlier than boys. In an MRI study published in Acta Paediatrica, all females had fully closed growth plates by age 19, while all males were fully closed by age 21. But closure isn’t a single event. It happens gradually, bone by bone, over several years during and after puberty.
Typical Timeline for Girls and Boys
For girls, the window of closure spans roughly ages 14 to 18. By age 14, half of girls already have closed growth plates in the heel and lower shinbone. By 17, the vast majority of plates are fused: 75% at the wrist, 85% at the thigh bone, and over 96% at the knee and ankle. By 19, closure is 100% across all measured sites.
Boys run about two years behind. At age 14, almost no growth plates have closed except in the heel, where about 18% of boys show complete fusion. By 17, only about a quarter of boys have a fully closed wrist plate, and roughly half have a closed thigh bone plate. It takes until age 19 for 90% or more of males to show closure at every site, and by 21, all males in the study had fully fused plates everywhere.
A practical rule: most children grow for about two more years after their fastest pubertal growth spurt. On average, girls stop gaining height around 13 to 15, and boys around 15 to 17.
Which Bones Close First
Growth plates don’t all shut down at once. They follow a consistent sequence. The heel bone (calcaneus) closes first. Next comes the lower shinbone (distal tibia), followed by the upper shinbone and the lower end of the thigh bone. The wrist (distal radius) is typically the last major growth plate to fuse. This pattern holds for both sexes, just shifted earlier in girls.
This sequence matters if you’re tracking growth or recovering from an injury. A closed growth plate at the ankle doesn’t mean you’ve stopped growing altogether. The wrist, knee, and thigh bone may still have active plates for another year or two.
Why Estrogen Is the Key Driver
Estrogen is the primary hormone responsible for closing growth plates, in both girls and boys. During puberty, rising estrogen levels trigger a growth spurt by stimulating the body’s growth hormone system. But estrogen also has a second, opposite effect: it gradually exhausts the cartilage cells that make bones grow longer. Each growth plate contains a limited supply of these stem-like cells, and estrogen speeds up how quickly they burn through their capacity to divide. Once those cells are depleted, the cartilage hardens into solid bone and growth stops permanently.
In boys, testosterone contributes to growth plate maturation, but not directly. The body converts testosterone into estrogen in various tissues, including the growth plate cartilage itself. This is why boys with higher estrogen exposure during puberty tend to close their plates sooner, and why girls, who produce more estrogen earlier, finish growing first. Children who enter puberty unusually early (precocious puberty) experience this same process on an accelerated timeline. They may grow fast initially but close their plates sooner, which can reduce their final adult height.
How Doctors Check Bone Age
The standard method is a simple X-ray of the left hand and wrist, compared against a reference atlas called the Greulich-Pyle atlas. A doctor matches the X-ray to standard images that correspond to specific “bone ages.” If your bone age is younger than your actual age, you likely have more growth remaining. If it matches or exceeds your age, your plates are near closure.
The method has real limitations. Its documented accuracy in the populations it was designed for is between 0.6 and 1.1 years off, but in more diverse populations the average error can reach 1.5 years, with some individual readings off by 2 years or more. It’s a useful estimate, not a precise countdown.
Signs That Growth Is Ending
There’s no reliable way to feel your growth plates closing. You won’t notice pain, clicking, or any obvious physical signal. The most practical indicators are pubertal milestones. Once a teenager has reached the late stages of puberty (full adult body hair, voice change complete in boys, regular menstrual cycles established in girls), the growth plates are close to fully fused or already done. A noticeable slowdown in height gain over six to twelve months is another strong clue.
Predicting the exact moment is difficult because different bones close at different times and individual variation is significant. Two boys the same age can be years apart in skeletal maturity.
Can Anything Speed Up or Delay Closure
Puberty timing is the biggest variable. Early puberty accelerates closure, and delayed puberty extends the window for growth. Certain medical conditions affecting hormone levels, thyroid function, or growth hormone production can shift the timeline in either direction.
One common concern is whether weightlifting closes growth plates early. A survey of 500 sports medicine experts found strong consensus that this idea is “very likely false.” Properly supervised resistance training is not associated with increased risk of growth plate injury in adolescents. There is no evidence that exercise accelerates plate closure.
What can genuinely damage a growth plate is a fracture through it. These injuries, called Salter-Harris fractures, range from mild to severe. Higher-grade fractures carry a real risk of premature fusion at the injury site, which can lead to a shorter limb or angular deformity as the child continues growing. The most severe type, where the growth plate is crushed, typically results in growth arrest at that location.
Can You Grow Taller After Plates Close
Once a growth plate has fully converted to solid bone, no further lengthening of that bone is possible. Growth velocity drops to zero after fusion, and final adult height is set. There are no supplements, exercises, or stretches that reopen a closed growth plate. The only medical intervention that can add height after closure is limb-lengthening surgery, which is a major orthopedic procedure reserved for significant limb length discrepancies.
Minor height fluctuations of up to a centimeter throughout the day are normal at any age, caused by compression and decompression of spinal discs. This is not the same as actual skeletal growth.