When Do Boys Stop Growing? What Pediatric Endocrinologists Want Parents to Know

By Dr. Christina Gerhardt, MD, and Dr. Toni Kim, MD, board-certified pediatric endocrinologists

Most boys stop growing in height between ages 16 and 18. Some gain small amounts until about 18 or 19. A bone age X-ray is the most reliable way to tell whether a boy still has growing left to do.

That range is wide because boys enter puberty at different times. A boy who starts early may be done at 15, while a late bloomer may still be growing in his last year of high school. Here is how the final growth years unfold.

When do boys stop growing in height? The timeline

Boys who start puberty early stop growing sooner, while late bloomers keep growing into their late teens.

Boys finish about two years later than girls, who usually reach adult height around 14 to 15. That's because boys start puberty later and their growth spurt peaks higher. For the girls' timeline, see when do girls stop growing.

Early maturers, late bloomers, and final height

When puberty starts changes when growth ends. Early maturers hit their growth spurt sooner and stop sooner. Late maturers, often called late bloomers, keep growing into their late teens.

On average, many late bloomers catch up and reach an adult height close to their peers'. But an average isn't a guarantee for one boy. Some boys who look like late bloomers have a treatable cause, such as a hormone deficiency, slowing their growth. Others start puberty early and stop growing before reaching their potential.

The only way to know which is happening is an evaluation while he's still growing. Our guide to delayed puberty in boys explains the signs, and our puberty in boys guide covers each stage.

How to tell if your son is done growing

These signs suggest growth is ending:

• He has needed to shave regularly for a year or more, and his voice has fully deepened.
• His height has changed by less than 1 cm (about ⅜ inch) over the past year, measured carefully.
• His shoe size has stayed the same for a year or more.

Age alone is a weak guide. Bone age predicts the end of growth better than birthday age. A bone age X-ray of the left hand and wrist shows how mature his skeleton is. When bone age matches his actual age and the growth plates have fused, growth is complete. Our article on when growth plates close explains how that X-ray is read.

For an estimate of where he's headed, try our child height calculator, which predicts adult height from both parents' heights.

His bones keep building after he stops growing taller

Growing taller and building strong bones are two different processes. Even after height growth stops, boys keep adding bone density through their late teens, and bone density in the spine can keep rising into the early twenties.

The late teens and early twenties are a window that sets up bone health for life. Enough calcium, vitamin D, protein, sleep, and weight-bearing exercise matter during these years, even if his height is already set.

When to see a pediatric endocrinologist

Don't wait to see if he catches up. Once the growth plates close, adult height can't change. An evaluation while he's still growing keeps every option open. Consider a visit if:

• He shows puberty signs, such as body odor with pubic hair or a growth spurt, before age 9.
• He has no signs of puberty by age 14.
• Between age 3 and the start of puberty, he grows less than about 2 inches a year.
• He has crossed down through two or more percentile lines on his growth chart.
• His projected height is well below what his parents' heights would predict.
• He went through puberty early and seems to have stopped growing early.
• He's noticeably shorter than his classmates and it's affecting him.

How LIFE evaluates growth in boys

At LIFE, a growth evaluation starts with the full picture. We review at least the last five years of his growth data, his family's growth patterns, and where he is in puberty. We order a bone age X-ray and targeted labs when they will answer a real question.

We also look at the whole child: nutrition, sleep, activity, and metabolic and inflammatory factors that can quietly affect growth. When treatment makes sense, options may include growth hormone therapy or medications that extend the growth window. Our guide Does My Child Need Growth Hormone? explains how that decision is made. The plan is built around your family's goals and values.

LIFE is a national practice. Families can meet our physicians by telehealth from anywhere, or in person at LIFE offices, including Austin, Atlanta, Beverly Hills, Newport Beach, and Nashville.

FAQ

At what age do boys stop growing? Most boys reach adult height between 16 and 18. Some gain small amounts until about 18 or 19, especially boys who started puberty late.

When do boys grow the most? Boys grow fastest around age 13½, gaining about 3.7 inches (9.5 cm) a year at the peak. Most boys hit this peak somewhere between 11 and 14.

When do boys' feet stop growing? Feet usually finish growing before height does, often around ages 14 to 16. A shoe size that stays the same for a year is one sign that overall growth is winding down.

Can a boy still grow after 18? Sometimes, but not much. Late-maturing boys may gain small amounts until about 19. Once the growth plates have fused, height can't increase further.

Do late bloomers end up shorter? Many late bloomers catch up and reach an adult height close to their peers'. Some boys who appear to be late bloomers have a medical cause slowing their growth, so an evaluation is the only way to know.

Is it too late for growth hormone at 15 or 16? Not necessarily. What matters is whether his growth plates are still open, which a bone age X-ray can show. The earlier he is evaluated, the more options remain.

Can anything help my son grow taller? Good sleep, enough protein and calories, and regular activity support healthy growth. Over-the-counter "height" supplements haven't been shown to increase adult height. If a medical cause is slowing his growth, treating it while his growth plates are open can help.

When do boys and girls stop growing? Boys typically reach adult height around 16 to 18. Girls usually finish earlier, around 14 to 15, because their puberty starts sooner.

Next Steps and About the Authors

Wondering whether your son has more growing to do?

If his growth, puberty timing, or predicted height has you questioning things, a clear answer is worth having while there's still time to act. Our physicians take the time to review his full growth history and explain what it means for him.

Schedule a consultation with LIFE

About Dr. Christina Gerhardt

Dr. Christina (Christi) Gerhardt is a board-certified pediatric endocrinologist with more than 20 years of experience. She is known on the West Coast for her care of growth and puberty, and for an integrative approach that looks at nutrition, lifestyle, and the whole child alongside medical treatment. Families chose her as a top pediatric endocrinologist for years running. Read Dr. Gerhardt's full bio.

About Dr. Toni Kim

Dr. Toni Kim is the founder of LIFE Pediatric Endocrinology and a board-certified pediatric endocrinologist with more than 20 years of experience, including many years in practice in New York. She earned her MD at Stony Brook University School of Medicine, completed her pediatric residency at New York Medical College, and trained in pediatric endocrinology at Children's Hospital Colorado. Her focus is growth and puberty disorders. She is known for an integrative approach that pairs medical treatment with nutrition and lifestyle medicine. Read Dr. Kim's full bio.

References

1. Diaz A, Ayala Castro L, Carrillo-Iregui A. Short Stature for the General Pediatrician. Pediatrics in Review. 2025.
2. Abbassi V. Growth and Normal Puberty. Pediatrics. 1998.
3. Mlakar M, Gradišek A, Luštrek M, et al. Adult Height Prediction Using the Growth Curve Comparison Method. PLoS One. 2022.
4. Debeko DD, Goshu AT. Height Growth Modeling in Ethiopian Children and Adolescents Aged 7–20 Years: A Prospective Cohort Study. BioMed Research International. 2024.
5. Sanders JO, Qiu X, Lu X, et al. The Uniform Pattern of Growth and Skeletal Maturation during the Human Adolescent Growth Spurt. Scientific Reports. 2017.
6. Al Alwan I, Alfaraidi H, Al Juraibah F, et al. Timing of Puberty and Late Pubertal Height in Saudi Schoolboys: Riyadh Puberty Study II. International Journal of Endocrinology. 2022.
7. Pineau JC. Longitudinal Growth of Stature in Boys According to Age and Puberty: Prediction of Adult Stature from the Age of 13 Years. American Journal of Human Biology. 2023.
8. Antonio L, Priskorn L, Holmboe SA, et al. Association Between Pubertal Timing and Bone and Body Composition in Young Adult Men. Scientific Reports. 2025.
9. McCormack SE, Cousminer DL, Chesi A, et al. Association Between Linear Growth and Bone Accrual in a Diverse Cohort of Children and Adolescents. JAMA Pediatrics. 2017.
10. Darelid A, Ohlsson C, Nilsson M, et al. Catch Up in Bone Acquisition in Young Adult Men With Late Normal Puberty. Journal of Bone and Mineral Research. 2012.

Medical disclaimer

This article is for general education and does not replace medical advice. Every child grows differently. Talk with your child's physician or a pediatric endocrinologist about your son's growth, puberty, or health before making any decisions about his care.