Will My Son Grow Taller After 16? What Bone Age and Growth Plates Reveal

Can Boys Still Grow After Age 16?

If your son has turned 16 and is still shorter than expected, you may be wondering whether he has another growth spurt ahead—or whether most of his height growth is already complete.

The most important answer is:

Turning 16 does not automatically mean a boy is finished growing.

Some 16-year-old boys have very little linear growth remaining, while others—especially later-maturing boys—may still have meaningful growth potential. Chronological age alone cannot tell you which situation applies. Puberty timing, recent height velocity, skeletal maturity, genetics, and the status of the growth plates provide much more useful information. The Pediatric Endocrine Society notes that normal puberty in boys begins across a broad range, with about 95% beginning between ages 9 and 14. Boys with later puberty can therefore have their adolescent growth spurt substantially later than peers.

This is why telling every family that "boys grow until 18"—or that "growth stops at 16"—is an oversimplification.

For parents trying to determine how much growth is actually left, the better questions are:

• When did puberty begin?
• How much has your son grown during the past 6–12 months?
• Is he still progressing through puberty?
• What is his bone age?
• Are his growth plates still sufficiently immature to allow additional linear growth?

A comprehensive evaluation can often answer these questions much more accurately than age alone.

The Most Important Concept: Biological Age Matters More Than Birthday Age

Two boys can both be 16 years old and have completely different growth potential.

Imagine two 16-year-olds.

One began puberty early, experienced his fastest growth at 13, has been shaving for several years, and has gained very little height during the last year.

The other entered puberty later, recently experienced voice changes, has a delayed bone age, and is still accelerating in height.

They may have the same chronological age, but biologically they are at very different stages of development.

The Pediatric Endocrine Society describes constitutional delay as a pattern in which skeletal maturation and puberty occur later than average. Bone age in these children may be delayed by a year, two years, or more, leaving additional time for growth compared with peers of the same chronological age.

This is why Constitutional Growth Delay is particularly important when evaluating teenage boys who appear to be "late bloomers."

When Does Puberty Normally Begin in Boys?

Puberty does not begin with facial hair or a deep voice.

The earliest clinical sign is usually enlargement of the testicles. The Pediatric Endocrine Society reports that about 95% of boys begin puberty between ages 9 and 14, with testicular enlargement typically occurring before penile growth and pubic hair development.

This is important because many parents don't recognize the beginning of puberty until much later.

Visible changes such as:

• Increased body hair
• Voice changes
• Acne
• Muscle development
• Facial hair

occur progressively as puberty advances.

By the time a teenager looks dramatically different, puberty may have been underway for several years.

When Do Boys Have Their Biggest Growth Spurt?

Boys generally experience their major pubertal growth spurt later than girls.

Pediatric endocrine educational material describes the male pubertal growth spurt as typically occurring around the later stages of puberty, approximately two years later than in girls. The American Academy of Pediatrics likewise notes that boys can gain roughly four inches during a year of rapid pubertal growth, although individual growth rates vary considerably.

For many boys, the fastest growth occurs during the early-to-middle teenage years rather than exactly at a particular birthday.

That's why Growth spurts age chart boys vs girls should always be interpreted as a general pattern—not a deadline.

How Much Can a Boy Grow After 16?

There is no single number that applies to every 16-year-old.

A boy who is already skeletally mature may have very little height remaining.

A boy whose puberty began late and whose skeletal age is significantly younger than his chronological age may still have substantially more time to grow. The American Academy of Pediatrics notes that boys with constitutional delayed puberty typically have their growth spurt later and often catch up by around age 18, while the Pediatric Endocrine Society similarly describes later growth in boys with constitutional delay.

Therefore, asking "How much will a 16-year-old grow?" is less useful than asking:

"How skeletally mature is this particular 16-year-old?"

Bone Age Is One of the Most Useful Tools for Answering That Question

A Bone age test for child height typically involves an X-ray of the left hand and wrist.

The image is compared with established skeletal maturity standards to estimate bone age.

The Endocrine Society explains that bone age is used to assess maturity of the growth plates and help determine how much growing time may remain.

This can be especially useful when chronological age and biological development don't seem to match.

For example:

16 years old with a bone age near 16:
Growth may be considerably further along.

16 years old with a substantially delayed bone age:
More growth potential may remain, depending on puberty, growth velocity, and the underlying reason for the delay.

Bone age is not a perfect crystal ball, but it can provide significantly more useful information than chronological age alone.

What Does a Delayed Bone Age Mean at 16?

A Delayed Bone Age means skeletal maturation is occurring later than expected for chronological age.

Possible explanations include:

• Constitutional growth delay
• Delayed puberty
• Growth hormone disorders
• Nutritional problems
• Chronic illness
• Other endocrine conditions

A delayed bone age may indicate additional time for linear growth, but it does not automatically guarantee a particular number of remaining inches.

The cause of the delay matters.

A healthy late bloomer with constitutional delay is very different from a teenager whose skeletal maturation is delayed because of an untreated endocrine disorder.

Growth Plates Determine Whether Bones Can Still Lengthen

Height increases primarily because long bones grow at specialized cartilage regions called growth plates, or epiphyseal plates.

As puberty progresses, sex hormones promote both the pubertal growth spurt and eventual skeletal maturation.

Once a growth plate has completely fused, that bone can no longer increase its length through normal linear growth.

This makes Growth plate closure age in children an important topic—but there is no universal age when every growth plate closes.

Timing varies according to:

• Puberty
• Genetics
• Skeletal maturity
• Sex hormone exposure
• Health conditions

This is one reason statements such as "all boys' growth plates close at 16" are medically misleading.

How Can You Tell Whether Growth Plates Are Still Open?

Parents cannot reliably determine growth plate status by looking at their teenager.

Height history and puberty signs provide clues, but imaging provides much better information about skeletal maturity.

A hand/wrist bone-age study is commonly used as the first step. The Endocrine Society specifically identifies bone-age X-ray as a method for evaluating bony growth-plate maturity and remaining growing time.

When parents are concerned that the treatment window before growth plates fuse may be narrowing, bone age can therefore be particularly useful.

Growth Velocity May Be Even More Important Than Current Height

One measurement should never be overlooked:

How much has your son actually grown during the past year?

This is called growth velocity.

A teenager who is 5'5" and still growing rapidly presents a different picture from a teenager who is 5'5" and has gained almost no height during the past 12–18 months.

Tracking Poor Growth Velocity helps identify children whose growth pattern may warrant further evaluation.

Growth charts are most useful when they contain accurate measurements over time rather than a single office measurement.

Parents should ideally keep records from:

• Pediatric appointments
• School physicals
• Sports physicals
• Previous endocrinology evaluations

These historical measurements can reveal whether the growth rate is accelerating, stable, or slowing.

Signs Your Son May Still Have Growth Remaining

No home observation can replace bone-age assessment, but certain patterns suggest that development may still be underway.

These can include:

• Puberty started later than classmates.
• There is a family history of late bloomers.
• Height is still increasing noticeably.
• Pubertal development is still progressing.
• Bone age is delayed.
• The adolescent growth spurt appears relatively recent.

Boys with Delayed Puberty may experience their growth spurt substantially later than average. The Pediatric Endocrine Society defines puberty as delayed when it has not begun by age 14 and notes that constitutional delay is a common reason for late puberty in boys.

Signs That Height Growth May Be Nearing Completion

Clues may include:

• Very little height change over the previous year
• Advanced pubertal development
• Skeletal age approaching maturity
• Growth plates appearing nearly fused on imaging

However, features such as facial hair or voice depth are not precise measures of remaining height.

Puberty unfolds on an individual timeline, which is why growth history and skeletal maturity are usually more useful than appearance alone.

Does a Deep Voice Mean a Boy Is Done Growing?

No.

A voice change indicates that puberty is progressing, but it does not independently establish whether growth plates have fused.

The American Academy of Pediatrics describes voice changes as occurring during middle adolescence while other puberty-related physical changes continue.

A boy can therefore still have some growth remaining after his voice deepens.

The amount cannot be accurately predicted from voice change alone.

Does Facial Hair Mean Growth Is Over?

Not necessarily.

Facial hair can indicate more advanced androgen exposure, but hair development varies significantly between individuals.

Genetics strongly influences:

• Facial hair density
• Body hair
• Timing of shaving
• Hair distribution

Using facial hair to estimate remaining inches is therefore unreliable.

If height potential matters clinically, growth velocity and bone age provide much more useful information.

Is a 16-Year-Old Who Hasn't Had a Major Growth Spurt a Late Bloomer?

Possibly.

One possibility is Constitutional Growth Delay, particularly when there is a family history of late puberty.

The Pediatric Endocrine Society notes that children with constitutional delay often have delayed skeletal maturation and later puberty while eventually reaching an adult height within the normal range.

But parents shouldn't automatically assume that every teenager who hasn't had a growth spurt is simply a late bloomer.

Other causes can include:

• Hormonal disorders
• Chronic disease
• Nutritional problems
• Hypogonadism
• Pituitary disorders

A teenager with unusually delayed development may therefore need evaluation rather than reassurance alone.

Could Low Growth Hormone Be the Reason a Teenager Is Short?

It can be, although true Growth Hormone Deficiency is uncommon.

The Endocrine Society describes pediatric growth hormone deficiency as a condition in which inadequate GH production interferes with normal childhood growth.

Signs that can increase concern include:

• Progressive slowing of height velocity
• Falling height percentiles
• Delayed bone age
• Height substantially below expected family range

Evaluation may include IGF-1, IGFBP-3, thyroid testing, other laboratory studies, and, when appropriate, specialized growth hormone testing.

What Does Low IGF-1 Mean in a 16-Year-Old?

Low IGF-1 can be relevant because IGF-1 mediates many effects of growth hormone.

However, one low result does not automatically diagnose GH deficiency.

Interpretation must consider:

• Age
• Sex
• Puberty stage
• Nutrition
• Chronic illness
• Laboratory reference ranges

This is why Growth Hormone Deficiency lab values in children need to be interpreted in the context of the entire growth pattern rather than as isolated numbers.

What If My Son Is 16 and Much Shorter Than His Parents?

Family height matters.

One reason to evaluate a teenager is when their growth trajectory is significantly below what would be expected based on parental heights.

Our guide to Child not growing but parents are tall explains why this pattern sometimes deserves closer examination.

Possible explanations include:

• Later maturation
• Endocrine disorders
• Nutritional problems
• Chronic disease
• Normal genetic variation

A growth evaluation can help distinguish among them.

Can a 16-Year-Old Still Benefit From a Growth Evaluation?

Yes—particularly if meaningful growth potential remains.

An evaluation does not automatically mean treatment.

The purpose is to determine:

1. How much growth has occurred recently?
2. Where is the teenager in puberty?
3. What is the bone age?
4. Is predicted adult height appropriate for the family?
5. Are there signs of an underlying growth disorder?
6. Is enough skeletal growth remaining for any intervention to potentially matter?

This is especially relevant when families are wondering about HGH therapy after puberty in kids or whether it is simply too late.

"After puberty" and "age 16" are not necessarily synonymous.

Skeletal maturity matters more.

Can HGH Make a 16-Year-Old Taller?

This depends heavily on diagnosis and skeletal maturity.

Growth hormone is an established treatment for certain pediatric growth disorders, including growth hormone deficiency, while eligibility and expected response depend on the clinical indication.

But one principle is critical:

Growth hormone cannot lengthen long bones after their growth plates have completely fused.

Therefore, families considering HGH for Children to Grow Taller should understand that evaluating remaining skeletal growth potential is essential before discussing expected height outcomes.

A child who begins treatment earlier in the growing years generally presents a very different opportunity from a teenager who is already approaching skeletal maturity.

What About a 14- or 15-Year-Old Who Is Already Growing Slowly?

Waiting simply because "boys grow late" can sometimes delay evaluation.

A child with HGH for 14-year-old still growing slow concerns should be evaluated based on growth velocity, puberty stage, bone age, and the overall clinical picture rather than being reassured solely because he is male.

Earlier recognition is particularly important when height percentiles are steadily declining.

Can Growth Hormone Help a Late Bloomer?

A true late bloomer does not automatically require growth hormone.

Many children with constitutional delay ultimately experience spontaneous later growth.

That's why Can growth hormone help late bloomers is a different question from whether a child has growth hormone deficiency.

Treatment decisions should depend on:

• Diagnosis
• Degree of short stature
• Pubertal development
• Growth velocity
• Bone age
• Remaining growth potential
• Risks and expected benefits

Not every short teenager needs medical treatment.

Can Sermorelin Help a Teenager Who Still Has Open Growth Plates?

Families sometimes ask about Sermorelin for Children as an alternative approach intended to stimulate endogenous growth hormone secretion.

However, the evidence supporting final adult-height improvement is much more established for FDA-approved recombinant growth hormone in appropriate pediatric indications than for compounded sermorelin.

Regardless of treatment being considered, open growth plates and sufficient remaining growth time are fundamental considerations.

A teenager approaching skeletal maturity has a much narrower biological window than a younger child with several years of growth remaining.

What Tests Might Be Used in a 16-Year-Old Growth Evaluation?

Testing should be individualized rather than ordering every available laboratory test.

Depending on the history and examination, Pediatric endocrine labs for height evaluation may include:

• IGF-1
• IGFBP-3
• Thyroid function testing
• Complete blood count
• Comprehensive metabolic panel
• Celiac screening
• Puberty-related hormones when indicated

If GH deficiency remains a concern after initial evaluation, a physician may consider the Child growth hormone testing process, which can include growth hormone stimulation testing.

Bone age is commonly added because it helps place laboratory findings into the context of remaining skeletal development.

What Parents Should Track at Home

Parents can gather surprisingly useful information before an evaluation.

Measure Height Accurately

Measure every 3–6 months rather than every few days.

Use:

• No shoes
• A hard floor
• A flat wall
• Consistent technique
• Similar time of day when possible

Small daily differences are not meaningful.

The trend over months matters much more.

Find Previous Height Records

Collect measurements from the past two or three years whenever possible.

These allow a clinician to calculate growth velocity.

Review Puberty Timing

Think about when major developmental changes began.

Ask About Family History

Was Dad a late bloomer?

Did an older brother continue growing later?

Did either parent have delayed puberty?

Family patterns can provide useful context.

What Parents Should Not Rely On

Several popular rules are too simplistic to determine whether growth remains.

"Boys always grow until 18."

Not necessarily.

"If he has facial hair, he is done growing."

Not necessarily.

"If he doesn't have a beard yet, he has years left."

Not necessarily.

"His feet are still growing, so his height must keep increasing."

Shoe size isn't an accurate measure of remaining linear growth.

"He should sleep before 10 p.m. to release growth hormone."

Growth hormone secretion is associated with sleep physiology rather than a universal 10 p.m. cutoff.

"If the growth plates are open at all, there must be several inches left."

Not necessarily.

Growth plates exist along a spectrum of skeletal maturation. "Open" does not automatically mean a large amount of height remains.

The Three Most Useful Questions for a 16-Year-Old Boy

If parents remember nothing else from this article, remember these three questions:

1. How Fast Is He Still Growing?

Recent height velocity shows whether active linear growth is continuing.

2. What Is His Bone Age?

Bone age provides information about skeletal maturity and remaining growth potential.

3. Where Is He in Puberty?

Later puberty can mean a later growth spurt, while advanced puberty generally means the period of rapid height gain is further along.

Together, these provide a far better answer than chronological age alone.

When Should Parents Consider a Pediatric Growth Evaluation?

Consider evaluation when:

• A 16-year-old has grown very little during the past year.
• Height percentile has steadily declined.
• He is substantially shorter than expected for his family.
• Puberty appears unusually early or late.
• Bone age is known to be delayed or advanced.
• There is concern about Poor Growth Velocity.
• He has not begun puberty by age 14.
• There are symptoms suggesting chronic illness or hormonal problems.
• The family wants to understand remaining growth potential before the growth plates mature further.

The Pediatric Endocrine Society considers lack of pubertal onset by age 14 in boys delayed and recommends evaluation when indicated.

Final Thoughts: Don't Use Age 16 as a Growth Deadline

The most important lesson for parents is simple:

A boy's 16th birthday does not tell you whether he is finished growing.

Boys mature on different timelines. Some enter puberty at 10 or 11, while others begin several years later. The Pediatric Endocrine Society recognizes normal pubertal onset across approximately ages 9–14, which alone demonstrates why two 16-year-olds may have very different amounts of growth remaining.

Instead of guessing from age, facial hair, voice changes, shoe size, or classmates' development, look at the measurements that actually help define the growth window:

growth velocity + puberty stage + bone age.

A Pediatric Growth Evaluation Checklist can help families understand the next steps when growth is uncertain.

If significant growth potential remains, identifying nutritional, hormonal, or medical factors early may provide more options than waiting until skeletal maturation is complete.

And if growth plates are already approaching maturity, knowing that information can still provide families with clarity and realistic expectations.

The goal should never be to promise a particular number of inches.

The goal is to understand where your son is in his individual growth timeline, how much biological opportunity may remain, and whether his growth pattern is healthy.

Medically Reviewed By

Dr. Devin Stone, ND

Dr. Devin Stone is a Doctor of Naturopathic Medicine and founder of HGHforChildren.com. His clinical focus includes pediatric growth optimization, growth hormone deficiency, delayed bone age assessment, constitutional growth delay, IGF-1 evaluation, and evidence-informed therapies designed to help children maximize healthy growth potential.

References

1. Pediatric Endocrine Society. Delayed Puberty – Boys. Normal male puberty begins across a broad age range; delayed puberty is generally considered when puberty has not started by age 14.
2. Pediatric Endocrine Society. Constitutional Growth Delay. Reviews delayed skeletal maturation, later puberty, and the role of bone-age assessment.
3. Endocrine Society. Growth and Short Stature. Describes bone-age X-ray as a tool for assessing growth-plate maturity and remaining growing time.
4. Endocrine Society. Growth Hormone Deficiency. Overview of pediatric GH deficiency and the role of growth hormone in normal growth.
5. American Academy of Pediatrics / HealthyChildren.org. Delayed Puberty in Boys. Reviews pubertal timing and later growth spurts in boys with constitutional delay.
6. American Academy of Pediatrics / HealthyChildren.org. Physical Development in Boys: What to Expect. Reviews normal male pubertal development.
7. American Academy of Pediatrics / HealthyChildren.org. Stages of Adolescence. Reviews physical and pubertal changes during adolescence.
8. Pediatric Endocrine Society. Disorders of Growth. Educational material describing pubertal growth patterns and later peak growth velocity in boys.