HEIGHTMOG
Epiphyseal Fusion · Reference Ages

What Age Do Growth Plates Close?

For height-critical long bones, growth plates typically close at 15–17 in females and 17–19 in males. Here is the complete reference with bone-by-bone ages, what drives the timing, and how to estimate where you stand.

Quick Reference: Closure Ages

15–17

Females — Height-critical bones

Femur (thigh) and tibia (shin). Most females have finished significant height growth by 16.

17–19

Males — Height-critical bones

Femur (thigh) and tibia (shin). Most males have minimal remaining growth by 20.

13–15

Females — Hand/wrist

First bones to fuse; used as bone-age reference.

15–17

Males — Hand/wrist

First bones to fuse; used as bone-age reference.

17–19

Females — Vertebrae (trunk height)

Small additional trunk height after long-bone closure.

19–22

Males — Vertebrae (trunk height)

Small additional trunk height. Last height-contributing plates.

22–25

Both sexes — Clavicle (collarbone)

Last plate to fuse. Does not contribute to standing height.

Sources: Greulich-Pyle Atlas (1959); Flecker (1942). Ranges = typical 10th–90th percentile.

What Determines the Age Growth Plates Close?

Growth plate closure is not primarily driven by chronological age — it is driven by bone age, which reflects your body's hormonal and skeletal maturity. Bone age can differ from chronological age by 1–3 years in healthy individuals. A 14-year-old with an advanced bone age might be closing plates that a 16-year-old with a delayed bone age has not yet reached.

The key hormonal driver of closure is estrogen. As levels rise during puberty, estrogen accelerates chondrocyte senescence — the cartilage cells in the growth plate stop dividing and begin calcifying (Kronenberg, 2003). This is why females close earlier (higher estrogen surge, earlier in puberty) and why males with aromatase deficiency (unable to produce estrogen) grow abnormally long into adulthood.

Three variables predict an individual's closure age better than population averages alone:

  1. Sex — females close ~2–3 years earlier
  2. Puberty timing — earlier puberty = earlier closure
  3. Genetics — parental puberty timing is the strongest inherited predictor

What Happens During Closure: Endochondral Ossification

Growth plate closure — formally called epiphyseal fusion — occurs in stages. As estrogen levels rise, proliferating chondrocytes (cartilage cells) in the zone of the growth plate slow and stop dividing. The cartilage matrix calcifies, blood vessels invade the zone, and osteoblasts replace cartilage with trabecular bone.

On radiograph (X-ray), the open growth plate appears as a dark line between the bone shaft (diaphysis) and the end cap (epiphysis). As closure progresses, this line narrows. When fusion is complete, the line is invisible — diaphysis and epiphysis form a single continuous bone structure. Radiologists can date closure precisely using reference atlases, which is why the wrist X-ray is the gold standard for bone-age assessment.

Is 18 the “Real” Cutoff Age?

Age 18 is often cited as the point when growth stops, but this is an oversimplification. What is true: by age 18, the vast majority of females (95%+) and most males (>80%) have completed fusion of their height-critical long bones. It is a reasonable population-level approximation.

What is not true: age 18 is not a biological switch. A male who entered puberty at 14 may have plates closing at 19–20. A male who entered puberty at 11 may be done by 16. Bone age, not birthdate, is the actual determinant.

95%+
of females with fused long bones by age 18
80%+
of males with fused long bones by age 18
~99%
of males with fused long bones by age 21

Estimates based on Greulich-Pyle atlas distribution data.

What Happens to Height After Growth Plates Close?

After epiphyseal fusion, bone elongation permanently ends. What can still change:

Vertebral disc health: Spinal discs rehydrate overnight; height measured in the morning is up to 1 cm taller than evening measurement. This is not growth — it reverses through the day.
Posture and muscle balance: Anterior pelvic tilt, rounded shoulders, and forward head posture reduce measured standing height. Correcting these can recover 0.5–1.5 inches of apparent height that was always there structurally.
Bone density changes: Bones thicken slightly with continued weight-bearing activity. This does not affect height but does affect bone health and fracture resistance.

Estimate Your Closure Status

Growth Plate Status Quiz

5 questions using Tanner-stage science. Estimates if your plates are still open, closing, or fused.

Take the quiz

5 Ways to Tell If Plates Are Closed

From X-ray (definitive) to growth velocity tracking — ranked by reliability.

Read guide

Medical disclaimer

The ages on this page represent population reference ranges, not diagnostic thresholds. If you have concerns about growth — including unusually early or late puberty, a significant drop in height percentile, or growth-related pain — consult a pediatric endocrinologist or your primary care physician. A bone-age X-ray of the wrist provides the only definitive assessment of skeletal maturity. Heightmog content is educational, not medical advice.

Related Pages

Growth Plates HubWhen Do Growth Plates Close?How to Tell If Yours Are ClosedHow to Keep Growth Plates OpenClosure Age by Sex (Tables)Height Predictor (Tool)

Frequently Asked Questions

What age do growth plates close?

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For height-critical long bones (femur and tibia), growth plates typically close between ages 15–17 in females and 17–19 in males. The earliest bones to fuse are hand and foot bones (13–15 in females, 15–17 in males). The last bone to fuse is the clavicle, around 22–25 in both sexes — but this does not affect standing height.

Do growth plates always close at the same age?

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No. The closure ages in population studies represent averages with a ±2–3 year range for normal individuals. Puberty timing is the dominant factor — late bloomers close later; early developers close earlier. Bone age (assessed by X-ray) can differ from chronological age by 1–3 years in healthy individuals.

What happens when growth plates close?

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When a growth plate closes, the cartilage zone is fully replaced by bone — a process called epiphyseal fusion. The dark line (epiphyseal line) visible on X-ray disappears. Once fused, the bone cannot elongate further through that plate. The process is permanent and irreversible under normal conditions.

Can you grow after growth plates close?

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No measurable bone elongation occurs after growth plate closure. Some people report perceived height changes in adulthood due to improved posture, disc rehydration after sleep, or weight loss (reduced compression). These are not growth — they are positional or compositional changes. True height growth requires open growth plates.

Is there a way to extend the age when growth plates close?

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No safe, evidence-based method exists to extend growth plate closure in healthy adolescents. The closure signal is driven by estrogen during puberty, a process governed by your genetic program. GnRH analogs can delay puberty in children with precocious puberty (under physician supervision) — but this is a medical treatment for a medical condition, not a lifestyle intervention.