When Do Growth Plates Close? When Exactly

Growth plates close at different times for different bones, but the general window is between ages 13 and 20. For most people, all growth plates have closed by their early twenties. Growth plates, also called epiphyseal plates, are areas of developing cartilage tissue near the ends of long bones. They are the last parts of a child’s bones to harden, or ossify. Once they harden into solid bone, the bone stops growing longer. That is when height increases stop.

What Are Growth Plates and Why Do They Close?

Growth plates are soft zones of cartilage at the ends of long bones like the femur, tibia, and radius. They are the engine of bone growth during childhood and adolescence. Hormones, especially estrogen and growth hormone, signal these plates to produce new bone cells. This is how children grow taller over time.

The process of closing is called epiphyseal fusion. As puberty ends, hormone levels shift. Estrogen, even in males, triggers the cartilage cells in the growth plate to stop dividing and turn into bone. Once that happens, the plate is gone. It is replaced by a thin line of dense bone called the epiphyseal line.

The exact timing depends on genetics, nutrition, sex, and certain medical conditions. Girls typically finish growing earlier than boys because they enter puberty sooner. The average growth plate closure for girls is around ages 14 to 16. For boys, it is closer to ages 16 to 18. But these are averages. Some people close earlier or later.

When Do Growth Plates Close in Girls vs. Boys?

Sex is the strongest predictor of growth plate timing. Girls generally experience growth plate closure two years earlier than boys. This aligns with the earlier onset of puberty in females.

Research from the American Academy of Pediatrics shows that girls’ growth plates in the legs often close around age 14. Their hand and wrist plates close slightly earlier, around age 13. Boys’ leg plates close around age 16, and hand plates around age 15. The spine’s growth plates are the last to close, often not fusing until the early twenties.

The clavicle, or collarbone, is the last growth plate to close in the human body. It can fuse as late as age 25. This is why forensic anthropologists use clavicle fusion to estimate age in skeletal remains.

Can You Tell If Your Growth Plates Are Still Open?

You cannot tell by looking or feeling. Growth plates are deep inside the bone ends. The only reliable way to know is through a medical imaging test.

A standard X-ray of the left hand and wrist is the most common method. Doctors compare the X-ray to a standardized atlas called the Greulich and Pyle atlas. This atlas shows typical bone development at each age. A radiologist can estimate how much growth potential remains based on how much cartilage is still visible.

Some people look for signs like recent height increases or growth spurts. If you have grown over an inch in the last six months, your plates are likely still open. If your height has been stable for two years, they are probably closed. But these are rough estimates. Only an X-ray gives a definitive answer.

What Happens If Growth Plates Close Early or Late?

Early closure means a child stops growing before reaching their genetic potential. This can happen due to conditions like precocious puberty, where puberty starts unusually early. The surge of estrogen causes the plates to fuse prematurely. Children with this condition may be tall for their age early on but end up shorter as adults.

Late closure is less common but can occur with delayed puberty. Some children simply have a later biological clock. Growth plates stay open longer, and they may continue growing into their late teens or early twenties. This is often genetic. If a parent grew until age 20, their child might too.

Certain medical conditions can also affect timing. Growth hormone deficiency can slow growth without necessarily delaying plate closure. Thyroid disorders can speed up or slow down bone age. In rare cases, tumors or trauma to the growth plate can cause one leg or arm to stop growing while the other continues. This leads to limb length discrepancies that sometimes require surgery.

Does Nutrition or Exercise Affect When Growth Plates Close?

Severe malnutrition can delay growth plate closure. Children who do not get enough calories, protein, or key vitamins like D and calcium may grow slowly and have delayed bone age. But for children eating a normal diet, extra nutrition will not keep plates open longer. Once the hormonal signal for closure arrives, nutrition cannot stop it.

Exercise does not cause growth plates to close earlier. That is a common myth. Intense physical activity in children does not fuse plates faster. However, overtraining without proper rest can injure growth plates, especially in the heel and knee. These injuries, called apophysitis, are painful but rarely affect overall height or closure timing.

What does affect closure timing is weight. Children with obesity tend to have advanced bone age. Excess body fat produces more estrogen, which can push growth plates to close earlier. This is one reason some children with obesity stop growing sooner than their peers.

Can Adults Increase Height After Growth Plates Close?

Once growth plates close, the long bones cannot grow longer. No supplement, exercise, or diet can reopen a fused growth plate. This is a biological fact.

Some people report height increases from spinal decompression exercises or hanging. What actually happens is temporary improvement in posture. The spine has discs between vertebrae that compress during the day. Stretching can reduce that compression, adding a few millimeters temporarily. But this is not bone growth. It is fluid shift in the discs.

Surgery is the only way to increase height after closure. Limb lengthening procedures involve cutting the bone and gradually pulling the ends apart with an external frame or internal rod. New bone forms in the gap. This is a major surgery with months of recovery and real risks like infection, nerve damage, and joint stiffness. It is not something to consider casually.

As of 2026, there is no clinical evidence that any drug, hormone therapy, or device can safely reopen growth plates in adults. The plates are replaced by solid bone. That bone does not revert to cartilage.

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