When Do Boys Stop Growing: Height, Genitals, And What To Expect

Maybe your like

Medical News TodaySubscribeWhat age do boys stop growing?

Medically reviewed by Karen Gill, M.D. — Written by Claire Sissons — Updated on June 25, 2025

Puberty duration
Genetics
Average height
FAQ
Contacting a doctor
Tips for growth
Summary

The first signs of puberty in boys usually appear around the age of 12 years. Most reach their adult height by the age of 16 to 18 years, but this can vary.

Growth during puberty happens over time, so it can be hard to know when it has finished.

Everyone grows at different rates, and puberty begins and ends at different times. Puberty can last anywhere from 2 to 5 years, so it is not always easy to predict when it will end.

A boy’s body goes through many changes during puberty. These changes can be embarrassing or confusing, but the process happens to everyone, and knowing what to expect can help.

We explain what to expect and how to know when boys are likely to stop growing.

adolescent boys in ballet class-1 — Thomas Barwick/Getty Images

How long does puberty last?

Puberty is the process of growth and change that happens in the body as children become adults.

Puberty is different for everyone and can start between 8 and 14. The average age for boys to show the first signs of puberty is 12 years, about 1 year after girls begin puberty.

The fastest rate of growth is usually 1 to 2 years after puberty has started.

Developing physically into an adult takes 2 to 5 years. Most boys will be fully developed and stop growing taller by age 16 to 18 years.

Onset of puberty and ethnicity

There is more research on the age at which puberty begins in girls than there is for boys. However, an older study by the American Academy of Pediatrics found that African American boys were likely to start puberty earlier than Hispanic or white boys.

The role of genes in boys’ growth

Genes play a role in a boy’growth, and parental height is a good indicator of how tall a child will be.

The mid-parental method is a way to predict a child’s adult height. To use it for boys:

add together the height of the mother and father in inches
divide this number by 2
add 2.5 inches

This calculation is approximate, and it is not possible to predict height accurately. Growth does tend to follow a curve, however, so if a person regularly plots a boy’s height on a graph throughout their childhood, it may be possible to track where the line is likely to end up.

Chronic illnesses, such as severe arthritis, and genetic conditions, such as Down syndrome, can cause a person to be shorter in adulthood than would otherwise be expected.

Average height in boys

Average height varies across the world. In the United States, the average height for an adult man is 5 feet 8 inches or 69 inches.

This average is found by adding the height measurements of a group of people together and then dividing by the number of people surveyed.

It does not mean that people above or below this height are unusually tall or small. It is important to remember that everyone is different.

Frequently asked questions

When do the genitals finish growing?

For boys, one of the first signs of puberty is the growth of the testicles and development of pubic hair. The penis first grows in length then width.Because puberty ends at different ages for different people, there is no set age at which the genitals will have completely developed. Once puberty is complete, the genitals are usually fully developed.

For boys, one of the first signs of puberty is the growth of the testicles and development of pubic hair. The penis first grows in length then width.

Because puberty ends at different ages for different people, there is no set age at which the genitals will have completely developed. Once puberty is complete, the genitals are usually fully developed.

When does body hair grow?

Pubic hair at the base of the penis grows first. At first, it may be light, thin, and straight, before becoming darker, thicker, and curlier.Facial hair and other body hair will develop after around 2 years of puberty. Development of body hair will usually stop at the end of puberty.

Pubic hair at the base of the penis grows first. At first, it may be light, thin, and straight, before becoming darker, thicker, and curlier.

Facial hair and other body hair will develop after around 2 years of puberty. Development of body hair will usually stop at the end of puberty.

What can affect growth in boys?

Factors such as diet and environment can affect growth. Worldwide, children with diets that cause nutritional deficiencies or malnutrition may not grow to be as tall or strong as those who have had plentiful and balanced meals.Illnesses, genetic conditions, and the use of some medications, such as corticosteroids, can all slow or limit growth.An imbalance of hormones might slow or speed up growth.

Illnesses, genetic conditions, and the use of some medications, such as corticosteroids, can all slow or limit growth.

An imbalance of hormones might slow or speed up growth.

When to contact a doctor

A parent or caregiver may wish to seek advice from a doctor if a boy:

is growing much faster or slower than expected
is much shorter or taller than other children their age
is growing very tall despite having shorter parents
has not started puberty by age 14

An X-ray of the hand and wrist can help judge how much more a child will grow.

Tips to ensure the best possible growth

All individuals have a maximum potential height. Some lifestyle measures may ensure a person reaches their full potential height, but a person cannot grow beyond this by using supplements or eating certain foods.

Eating a nutritious diet, getting enough sleep, and being active are vital. There are many ways to stay active, from joining a sports team to helping with household chores.

Teenagers need 8 to 10 hours of sleep per night. A healthy sleep pattern means going to bed at around the same time each night and not staying up too late. There is no evidence that getting enough sleep positively affects a person’s growth, but as the body repairs tissues and muscles during sleep, it may help.

During puberty, boys may be shorter or taller than other boys their age, which can be hard to deal with. Understanding the changes their body is going through and being able to find information about puberty can help.

Boys should be reassured that growing takes time, and everyone is different. Developing good self-esteem through positive family relationships, friendships, hobbies, and interests can all help boys thrive throughout puberty.

Summary

Boys typically stop growing around age 16 to 18 years, but this can vary, and some boys stop growing later. A child’s genes play an important role in determining how tall they will be as an adult, but this is not the only influence. Lifestyle, nutrition, and activity levels are also important.

There are no supplements that can help a person grow taller, but making healthy lifestyle choices, such as getting 8 to 10 hours of sleep per night, can help with overall health.

If a person is concerned about their height, they can talk with a doctor. Certain medical conditions can influence growth, and a doctor may wish to test for them.

Endocrinology
Genetics
Pediatrics / Children's Health
Parenthood
Teens / Adolescents

How we reviewed this article:

SourcesMedical News Today has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical journals and associations. We only use quality, credible sources to ensure content accuracy and integrity. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

About sleep. (2024).https://www.cdc.gov/sleep/about/index.html
Body measurements. (2021).https://www.cdc.gov/nchs/fastats/body-measurements.htm
Breehl L, et al. (2023). Physiology, Puberty.https://www.ncbi.nlm.nih.gov/books/NBK534827/
Early or delayed puberty. (2022).https://www.nhs.uk/conditions/early-or-delayed-puberty/
Herman-Giddens ME, et al. (2012). Secondary sexual characteristics in boys: Data from the pediatric research in office settings network.https://publications.aap.org/pediatrics/article-abstract/130/5/e1058/32411/Secondary-Sexual-Characteristics-in-Boys-Data-From?redirectedFrom=fulltext
Storr HL, et al. (2023). Assessment of childhood short stature: A GP guide.https://bjgp.org/content/73/729/184
Umer M, et al. (2023). Skeletal age evaluation using hand X-rays to determine growth problems.https://pmc.ncbi.nlm.nih.gov/articles/PMC10702717/

Share this article

Medically reviewed by Karen Gill, M.D. — Written by Claire Sissons — Updated on June 25, 2025

Latest news

5 healthy habits may help keep the brain younger, even with chronic pain
A 1-week social media break could boost your mental health
Certain changes in driving patterns may point to cognitive decline, dementia
Eating takeout food too often may increase cardiovascular disease risk
Between sleep and exercise, choose sleep, research suggests

Related Coverage

At what age do girls stop growing?Medically reviewed by Karen Gill, M.D.
A look at when girls stop growing. Included is detail on when puberty starts and finishes, in addition to what can prevent or delay development.
READ MORE
When does the penis start and stop growing?
The penis tends to stop growing in both length and girth at the end of puberty. Learn more about penis growth in this article.
READ MORE
How tall is the average man?Medically reviewed by Debra Sullivan, Ph.D., MSN, R.N., CNE, COI
Average height varies according to geographical location, nutrition, exposure to disease, genetics, and some other factors. Learn about the average…
READ MORE
What factors influence a person’s height?Medically reviewed by Mia Armstrong, MD
Genes determine about 90% of a person's height, but other factors can also affect it. Read about how people can increase their height during…
READ MORE
Tips for preparing your child for surgeryMedically reviewed by Mia Armstrong, MDREAD MORE

Tag » When Do Men Stop Puberty

Health Conditions

Health Products

News

Original Series

Podcasts

General Health

Health Tools

Quizzes

About Medical News Today

Find Community

Follow Us