What is the Average Weight Of A 9-Year-Old?

How to Tell if Your 9-Year-Old is Overweight or Underweight

By 9 years old, most kids have started to develop a degree of independence in terms of diet and exercise. They might choose their own snacks and prepare some of their own meals, as well as pursue athletic activities on a schedule that suits their personal level of interest. For a parent, it can be tricky to find a balance between intervening in a 9-year-old's diet and exercise choices and encouraging their independence.

One way to tell if your child's size is healthy for her age is to look at your child's weight compared to average growth charts. Being heavier or lighter than the average 9-year-old does not in itself indicate that your child is overweight or underweight. Consider numerous other factors to get a clear picture of her overall health, and discuss any genuine concerns with your child's doctor.

Weight Averages for 9-Year Olds

At regular check-ups, your child's pediatrician will compare his weight on a chart to calculate the percentile in which it lies. These height and weight charts are published by both the Centers for Disease Control (CDC) and World Health Organization (WHO) and can be found online. There are separate charts for boys and girls.

Using the 50th percentile data as "average," the average weight for a 9-year-old boy is 63 pounds and the average weight for a 9-year-old girl is 64 pounds, according to the CDC. The WHO charts show the average weight for both boys and girls at 9 years old to be 61.7 pounds. The CDC chart shows the middle 50 percent, i.e. the 25th to 75th percentiles, to be between 57 and 72 pounds for girls and between 57 and 70 pounds for boys.

Using Weight Charts

Growth Charts for Determining Normal Teen Weight

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Between doctors' appointments, you can estimate your 9-year old's weight percentile by examining the appropriate chart as follows: trace along the vertical line above "9 years" marked on the horizontal age axis; trace across from the line on the vertical axis that matches your child's weight; mark a dot on the chart where the two lines intersect. The dot will probably lie between two diagonal lines charted on the graph that indicate percentiles, allowing you to estimate the percentile of your child's weight.

It's more useful to look at your 9-year old's height percentile in conjunction with weight. A healthy weight for a very tall 9-year-old is more than that for a short 9-year-old, of course, so consider whether the weight and height percentiles you've estimated for your child are somewhat in line. If they don't seem to be in proportion, for example, if your child is in the 25th percentile for height but the 80th for weight, this can indicate that he is overweight.

Average Weight Versus Healthy Weight

Comparing your child's weight to the average 9-year-old's weight is not enough by itself to paint an accurate picture of her health. The following factors must also be considered:

  • Genetics. Your child's height and build are genetic and cannot be changed. 
  • Growth spurts. Children don't necessarily grow and gain weight evenly throughout a year.
  • Early puberty. In girls, the earliest signs of puberty, including developing breasts and rounder hips, can begin as young as 8 or 9.
  • Varying activity level. Some children are much more active during warmer months or certain sports seasons, which can result in some weight gain during less active times.
  • Medical issues. A sudden weight gain, weight loss or stalled growth might be caused by an underlying medical issue, so it's important to discuss concerns about your child's weight with a health care professional.
Boys: Average Height and Weight
Age Height Weight

2 years

2 ft 11 in

30 lb 10 oz

3 years

3 ft 2 in

31 lb 12 oz

4 years

3 ft 4 in

36 lbs

5 years

3 ft 7 in

40 lbs 8 oz

6 years

3 ft 9 in

45 lb 8 oz

7 years

4 ft

50 lb 8 oz

8 years

4 ft 2 in

56 lb 8 oz

9 years

4 ft 4 in

63 lbs

10 years

4 ft 6 in

70 lb 8 oz

11 years

4 ft 8 in

78 lb 8 oz

12 years

4 ft 10 in

88 lbs

13 years

5 ft 1 in

100 lbs

14 years

5 ft 4 in

112 lbs

15 years

5 ft 7 in

123 lb 8 oz

16 years

5 ft 8 in

134 lbs

17 years

5 ft 9 in

142 lbs

18 years

5 ft 9 in

147 lb 8 oz

19 years

5 ft 9 in

152 lbs

20 years

5 ft 10 in

155 lbs

Data from the CDC

Encouraging a Healthy Lifestyle

The Average Weight and Height for a 12-Year-Old

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The best way to encourage your 9-year old to maintain a healthy weight is by teaching about and demonstrating a healthy lifestyle i.e. eating a balanced diet, exercising regularly and getting enough sleep. Remember to be sensitive to your child's feelings and emphasize health over looks.

As a parent, you have control over most of the meals and snacks your child eats, so provide plenty of fruits, vegetables and whole grains, plus meats, fish and dairy, all in moderate portions. Limit fatty, sugary and highly processed foods, including sugary drinks such as juice and sodas. A simple approach is to be strict while food shopping – if you don't bring unhealthy foods into the house, your children (and you) won't be able to snack on them. Learning about and trying healthy foods is something you can do together as a family. Look up new recipes and prepare them together – as a bonus you'll teach your child valuable cooking skills.

Also encourage your child to play sports or do other active pursuits for at least 30 minutes a day, and put limits on his screen time. Being active is something you can do as a family. You could plan active adventures, such as hikes and bike rides, or make a commitment to walk the dog together every day. Discuss what sports your 9-year old might like to try, and look into local clubs, parks and rec. departments and after-school programs that offer activities for kids.