Before your child was even born, you probably wondered about their hair color, eye color, and height. While you can’t predict everything, there are some clues to help you tell how tall your child may be.

A number of factors go into determining how tall your child will be. Some of these are:


Boys tend to be taller than girls.

Genetic Factors

A person’s height tends to run in families. Most people in a certain family will grow at similar rates and be of similar height. However, this isn’t to say short parents may not have an extremely tall child.

Health Status

If a child has certain medical conditions, it can affect their growth. One example is Marfan syndrome, a genetic disorder that causes those who have it to be unusually tall. Conditions that may cause a child to be shorter include arthritis, celiac disease, and cancers. Also, children who took certain medicines, like corticosteroids used over a long period of time, may not grow as tall.


Overweight children will often be taller, while underweight or malnourished children may be shorter. However, this doesn’t always predict a child’s ultimate height.

There are several formulas that can estimate how tall a child might be. While none have been proven to definitely predict your child’s height, they can help give you a rough estimate.

Height at Young Age Method

For boys, double your son’s height at age 2. For girls, double your child’s height at 18 months.

Example: A girl is 31 inches at age 18 months. 31 doubled = 62 inches, or 5 feet, 2 inches tall.

Mother and Father’s Height Average

Calculate the mother and father’s height in inches and add them together. Add 5 inches for a boy or subtract 5 inches for a girl, to this total. Divide the remaining number by two.

Example: A boy’s mother is 5 feet, 6 inches tall (66 inches), while the father is 6 feet tall (72 inches):

  • 66 + 72 = 138 inches
  • 138 + 5 inches for a boy = 143
  • 143 divided by 2 = 71.5 inches

The boy will be an estimated 5 feet, 10 inches tall. The results are usually within 4 inches, plus or minus.

Bone Age X-Ray

A doctor can take an X-ray of your child’s hand and wrist. This X-ray can show the growth plates of a child’s bones. As a child ages, the growth plates become thinner. When a child is finished growing, the growth plates will disappear. A doctor can use a bone age study to determine how much longer, and taller, a child may grow.

Girls and boys will typically experience a significant growth spurt in puberty.

This occurs at different ages for each gender. According to Nemours, girls usually begin puberty between ages 8 and 13. During this time, they will start growing breasts and begin getting their periods. Boys will typically begin puberty between ages 9 and 14.

Because girls tend to hit their growth spurts first, they tend to stop growing at a younger age, usually around age 16. Boys will often continue to grow until age 18.

However, children grow at different rates. How long a child may grow can depend upon when they go through puberty. If a child goes through puberty later than most children their age, they may grow until a later age as well.

If you’re worried your child may not be growing at an expected rate, talk to their doctor.

They can show you a growth chart of average growth, given your child’s age and gender. Your child’s doctor can use a chart to plot their growth. If your child has suddenly seemed to slow in growth or is much below the average growth curve, your child’s doctor may refer you to an endocrinologist. This doctor specializes in hormones, including growth hormones that play a role in how tall your child is. If your child’s doctor is concerned that your child may have a genetic condition, they may refer you to a genetic specialist.

Examples of factors that affect your child’s growth include:

  • absorption issues with food
  • kidney disorders
  • overeating and nutritional status
  • thyroid disorders
  • growth hormone disorders
  • heart or lung disorders

An endocrinologist can test your child’s blood and perform other tests to determine what factors may affect their growth.

If you’re concerned about your child’s growth, it’s important to seek medical care before they complete puberty, as they will usually stop growing after that time. Treatments may be available for children who are not growing as expected. If you have concerns, your child’s pediatrician is an excellent place to start.