The Average Weight and Height for 9-Year-Old Boys and Girls

Kids at 9 years old are about to enter puberty. So, you should carefully take care of their health and growth to avoid the danger of hindering their development during adolescence. As parents, do you know the average weight and height for 9-year-old boys and girls? Read this article to learn more.

Factors that affect the weight and height of a 9-year-old


If parents have average statures, their children will likely develop to about the same appearance. That is because they inherit their parents’ DNA, which makes them mature and become more identical to their dad and mom.


It is believed that boys may be taller than girls in some situations as girls have two X chromosomes and hit puberty earlier than boys.


Growth hormones are mainly produced in the pituitary gland and are the most crucial hormones for growth. However, some health conditions might prevent the amount that the body might release, affecting height growth. For example, kids with a congenital growth hormone deficiency only grow at a slower rate compared to others. Also, thyroid hormones and sex hormones (like estrogen and testosterone) affect growth during puberty.

Health conditions

Below are some health issues that might affect children’s growth.

  • Basic morbidities, like digestive problems, disorders of the lung, kidney, or heart, and continual stress

  • Chronic illnesses, such as arthritis, celiac disease, or cancer

  • Chromosomal abnormalities

  • Reduced or excess growth hormone production

The health of pregnant women

If a woman has a poor diet during her pregnancy, the chances of her kid being born are smaller. Or if her weight has increased remarkably during this period, this is a signal that the kid is possibly to be bigger.

What is the average weight of a 9-year-old?

According to the weight charts of the Centers for Disease Control (CDC), you can find out the mean weight for a 9-year-old boy is 63 pounds (28.5 kilograms) and 64 pounds (29 kilograms) for a 9-year-old girl [1, 2]. Meanwhile, the WHO charts show the mean weight for both 9-year-old boys and girls is about 61.7 pounds (27.9 kilograms) [3, 4].


What is the average height of a 9-year-old?

At age 9, the mean height of boys and girls share the same number; that is, 52.5 inches (133.3 centimeters), according to CDC [1, 2]. But in some cases, a 9-year-old might be taller or shorter than that number since height is affected by many different factors.

Ways to help 9-year-old boys and girls grow comprehensively



Consuming foods is a great way to fuel your kids as well as help their bodies grow. They need a wide range of vitamins and minerals from five food groups, including fruits, veggies, dairy, lean proteins, and grains. Also, make sure they have breakfast, lunch, dinner, and two healthy snacks daily to get enough energy.

It is fine to make a specific plan for each meal daily if you are too busy. For instance, you could write some dishes for Monday, like whole wheat toast with two poached eggs, one banana, and a cup of yogurt for a mid-morning snack, chicken breast and salad for lunch, hummus and veggies for an afternoon snack, steak, steamed veggies, and salad for dinner, and a cup of fresh fruits for dessert.

Vitamin supplements

If you are worried that your kids are not receiving enough nutrients from food, you might consider children’s vitamins. However, not all vitamins are good and safe for their health. So, make sure you ask your doctor before buying anything.

Bad habits

Kids at any age crave sugary snacks and junk food, and they tend to consume more sugar and sodium to satisfy an urgent desire, which might result in high blood glucose and bad cholesterol. Overeating is another bad habit that leads to diabetes and obesity. These health conditions might prevent the release of growth hormones and stop healthy bone growth.

As parents, you should help them replace unhealthy foods with other healthy options. For instance, instead of eating white rice, you can change to brown rice, a cake with fresh fruits instead of a cake with frosting, or a salad instead of fries.


Drinking enough water helps the body grow better and faster. Boys at 9 years old should drink 10 cups every day, while girls should drink 8 cups. But if your children are physically active or the weather is hot outside, they can drink more.


Similar to nutrition, doing any physical activities or simply moving the body is vital for growing tall and fit.

  • Stretching is a great way to extend the spine and improve posture at all times.

  • Hanging from bars also aids in elongating the spine as well as making the muscles of the back and arms stronger.

  • Yoga poses allow the body to stretch completely, encouraging growth in height.

  • Skipping is a fun and simple exercise that helps fully promote your children’s growth.

  • Swimming is known as a full-body exercise that can work all the muscles of the body.

  • Jogging helps strengthen the bones in the legs and stimulates growth hormones.

Make a schedule so your children can indulge in any exercises for at least 30 minutes a day. Or you can join in with them to create a close bond.



If you want your 9-year-old child to grow taller, stronger, and healthier, make sure he gets enough sleep, between 9 and 11 hours of sleep a night. This is because the growth hormones are only secreted when he is in a deep sleep. And to help your children to get better sleep, you should:

  • Set a consistent sleep schedule, even on the weekends.

  • Establish a bedtime routine, like brushing their teeth, taking a bath, wearing comfortable pajamas, and reading a book.

  • Turn electric devices off an hour before bedtime.

  • Prepare a quiet and dimly lit place to sleep.

  • Avoid sugary and caffeine drinks as well as vigorous exercises, especially in the late afternoon or evening.


Vitamin D is vital for improving muscle and bone growth since it helps the body absorb calcium from the diet. And if you are looking for an excellent source of vitamin D, sunlight is the best answer. Encourage your kids to play outdoor activities instead of staying at home and playing video games. But always wear sunscreen to protect their skin from harmful UV rays of the sun and keep them indoors during the hottest hours of the day.

In sum,

Knowing the average height and weight can help parents know how heavy and tall their kids are in comparison with other children at 9. And do not forget to apply all the methods mentioned above to help them grow tall and strong.

Read more: How Tall Is An Average Indian?


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