Growth Timeline · Bone Fusion

When Do Growth Plates Close?

Growth plates in the height-critical long bones (femur and tibia) typically fuse between ages 15–17 in females and 17–19 in males. Timing varies by bone, sex, and individual biology — here is what the research shows.

Growth Plate Closure Ages by Bone and Sex

Ranges based on Greulich-Pyle Radiographic Atlas (1959) and Flecker (1942). Individual variation of ±2–3 years is normal and expected. “Height-critical” bones are those where fusion directly ends vertical stature gain.

BoneFemaleMale
Hand / Wrist (distal phalanges)13–1515–17
Radius / Ulna (forearm)14–1616–18
Humerus (upper arm)14–1616–18
Tibia / Fibula (shin, height-critical) ★ height-critical15–1717–19
Femur (thigh, height-critical) ★ height-critical15–1717–19
Vertebrae (ring apophyses)17–1919–22
Clavicle (collarbone, medial end)22–2522–25

All ages in years. Sources: Greulich-Pyle Atlas (1959); Flecker (1942).

Why Do Females' Growth Plates Close Earlier?

The primary driver is estrogen. Both males and females produce estrogen, but females do so in much larger quantities beginning at earlier ages. High estrogen levels accelerate chondrocyte senescence in the growth plates — in plain terms, estrogen “tells” the growth plates to stop producing new cartilage and begin calcifying.

Males experience a significant testosterone surge in puberty, but testosterone must first be converted to estrogen (via the enzyme aromatase) to exert this plate-closing effect. This conversion happens more slowly in males, delaying the closure signal by roughly 2–3 years.

Interestingly, males with aromatase deficiency — a rare condition where testosterone cannot be converted to estrogen — continue growing well into their 20s and can reach exceptional heights. This genetic edge case confirms that estrogen, not testosterone itself, is the key closure signal (Carani et al., 1997, NEJM).

Tanner Stage and Growth Plate Closure

Tanner staging (Tanner, 1962) classifies puberty development on a 5-point scale. Growth plate status correlates strongly with Tanner stage — better than with chronological age alone, because puberty timing varies significantly between individuals.

Tanner 1

Pre-pubescent. Growth plates are wide open. Linear growth continues at childhood rate (~5–6 cm/yr).

Tanner 2–3

Early to mid-puberty. Growth plates active; peak height velocity (PHV) is approaching or occurring. Fastest growth of life happens here.

Tanner 4

Late puberty. Growth slows. Plates beginning to narrow in distal bones. Some remaining height may still be gained in long bones.

Tanner 5

Skeletal maturity. Most plates fused. Clinically, this stage marks the end of significant height gain. Vertebral growth may continue marginally.

Peak Height Velocity: Your Fastest Growth Window

Peak height velocity (PHV) is the moment of fastest linear growth during puberty. It occurs at approximately:

  • Females: approximately age 11.5–12, averaging ~8–9 cm/year at peak (Tanner & Davies, 1985)
  • Males: approximately age 13.5–14, averaging ~9–10 cm/year at peak (Tanner & Davies, 1985)

After PHV, growth decelerates rapidly. By the time most adolescents are in their mid teens, growth has slowed to 1–2 cm per year, and plates are approaching closure. Recognizing where you are relative to PHV is one of the most useful practical signals for estimating remaining growth potential.

Why the Age Ranges Are Wide (±2–3 Years)

Population-level closure ages are averages across diverse individuals. Several factors shift an individual's closure timing:

Genetic timing

The strongest predictor. Parental puberty timing correlates with offspring timing.

Nutrition / body composition

Higher body fat is associated with earlier puberty onset (especially in females), which pulls closure earlier.

Chronic illness

Conditions like inflammatory bowel disease, celiac disease, or chronic kidney disease can delay growth and closure.

Hormonal disorders

Hypo/hyperthyroidism, GH deficiency, and precocious/delayed puberty all shift timing meaningfully.

When to see a doctor

If a child falls off their height growth channel (crosses two major percentile lines downward on a CDC growth chart), shows signs of puberty before age 8 (females) or 9 (males), or has not started puberty by 13 (females) or 14 (males), evaluation by a pediatric endocrinologist is appropriate. Heightmog content is educational, not medical advice.

Explore the Growth Plates Cluster

Frequently Asked Questions

When do growth plates close in males?

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In males, the height-determining long bones (femur and tibia) typically fuse between ages 17–19. Hand and wrist plates close earlier, around 15–17. The last bone to fuse is the clavicle (collarbone), around 22–25, but this does not contribute to height. Individual variation of ±2–3 years is normal.

When do growth plates close in females?

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In females, growth plates fuse roughly 2–3 years earlier than in males. The femur and tibia typically close between 15–17. Hand plates close around 13–15. Vertebral growth continues until around 17–19 in females, adding a small amount of trunk height.

What is the last growth plate to close?

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The medial clavicle (inner collarbone) is the last growth plate to fuse in both sexes, typically around age 22–25. However, this bone does not contribute to standing height. For height purposes, the relevant last plates to close are the vertebral ring apophyses, which continue maturing until the early 20s in males.

Can growth plates close early?

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Yes. Precocious puberty, certain hormonal disorders, steroid abuse, and radiation exposure to growth plate regions can all cause premature closure. If a child's height trajectory drops significantly below their expected percentile, early evaluation by a pediatric endocrinologist is warranted.

Do you stop growing the moment growth plates close?

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Yes and no. Bone elongation stops when the epiphyseal plate ossifies. However, spinal disc hydration changes and posture improvements can affect measured height by 0.5–1 inch even in adulthood — these are not growth, but they are measurable. True bone growth ends with plate closure.