Boys seem to grow at incredible rates, which may make any parent wonder: When do boys stop growing?

According to the National Health Service (NHS), most boys complete their growth by the time they’re 16 years old. Some boys may continue to grow another inch or so in their later teen years.

Keep reading to learn more about growth in boys and what to expect.

Boys go through a growth spurt during puberty. However, the rates of growth can vary a lot because boys go through puberty at different ages. On average, boys tend to grow around 3 inches (or 7.6 centimeters) per year during this period.

The age of a boy when he goes through puberty doesn’t affect how tall he’ll eventually be, but it’ll affect when his growth starts and stops.

Boys tend to fall into two categories:

  • early maturers, starting puberty around the age 11 or 12 years old
  • late maturers, starting puberty around the age 13 or 14 years old

Both categories usually gain the same average amount of inches in height, but the late maturers tend to grow at a faster rate to make up for lost time. During puberty, the peak height that boys reach is 92 percent of their adult height.

Boys who have growth restrictions before they start puberty still gain the same average amount of inches in height during puberty. They never quite make up for any deficits from before puberty.

For American men 20 years old and up, the average age-adjusted height is 69.1 inches (175.4 cm), or just over 5 feet 9 inches tall.

Height by age

At 10 years old, the earliest start of puberty, half of all boys will be under 54.5 inches (138.5 cm). The median heights listed below are taken from a CDC chart from 2000:

Age (years)50th percentile height for boys (inches and centimeters)
850.4 in. (128 cm)
952.6 in. (133.5 cm)
1054.5 in. (138.5 cm)
1156. 4 in. (143.5 cm)
1258.7 in. (149 cm)
1361.4 in. (156 cm)
1464.6 in. (164 cm)
1566.9 in. (170 cm)
1668.3 in. (173.5 cm)
1769.1 in. (175.5 cm)
1869.3 in. (176 cm)

Genes from both parents play a role in determining height and growth for both boys and girls. Other factors such as diet, activity level, and the mother's nutrition during pregnancy also affect height.

The mid-parental method is one way of predicting how tall a child will be. In this method, you add up the heights of the parents (in inches), and then divide the number by 2.

Add 2.5 inches to this number to get the predicted height for a boy. Subtract 2.5 inches from this number to get the predicted height for a girl.

For example, take a boy with a father who’s 70 inches tall and a mother who’s 62 inches tall.

  1. 70 + 62 = 132
  2. 132 / 2 = 66
  3. 66 + 2.5 = 68.5

The boy’s predicted height would be 68.5 inches, or 5 feet 8.5 inches tall.

This isn’t exact, however. Children may end up as much as four inches taller or shorter than the height predicted by this method.

Boys and girls grow differently. Boys tend to grow at a faster rate during childhood. On average, boys also tend to be taller than girls. That’s why doctors use separate growth charts for boys and girls to measure growth over time.

The percentile your child falls into isn’t as important as consistency. If your child drops from the 40th percentile to the 20th, for instance, their doctor may recommend tests to determine an underlying cause.

There are many possible causes of growth delays, including:

Boys who are overweight and obese tend to have lower growth rates. Malnutrition during childhood could also delay growth.

Growth delays may be most noticeable during infanthood, which is why it’s important to keep on schedule with well-child visits. At each visit, your child’s pediatrician will track growth. That allows the doctor to detect a problem right away.

In general, boys tend to stop growing around the age of 16. Many factors can affect growth and, ultimately, height. These include environmental factors as well as nutrition and physical activity levels.

If you’re concerned about possible growth delays, contact your child’s doctor.