What’s the Average Weight for 13-year-old Boys and Girls? – 2024

On average, 13-year-old boys weigh between 75 and 145 pounds, while 13-year-old girls weigh between 76 and 148 pounds. For boys, the weight at the 50th percentile is around 100 pounds, and for girls, it is around 101 pounds. It’s important to remember that being within this range is considered average and not necessarily overweight or underweight.

During puberty, each child goes through changes at their own pace. They can grow as much as 10 inches and develop muscle, fat, and bone, transforming into their adult form. These changes can occur suddenly and involve rapid weight gain, which may make children feel self-conscious as they adapt to their new bodies. Some kids may start puberty as early as age 8, while others may not begin until their early teens. As a result, there is a wide range of “normal” weights, shapes, and sizes.

What Is The Average Weight For A 13-Year-Old
What Is The Average Weight For A 13-Year-Old?

Also Read – Chrissy Metz transformation on Ellen.

According to the CDC, the average weight for 13-year-old boys is about 100.5 pounds, and for girls, it’s around 101.5 pounds. Remember, these are just average numbers, and what’s considered a healthy weight can vary based on factors like height, body type, and muscle mass.

Average Weight For 13 Year Old – Girls And Boys

The average weight for 13-year-olds, both girls and boys, is influenced by two main factors: body fat and muscle mass/bone density.

Body Fat

This is soft tissue found beneath the skin that stores extra calories as energy, provides cushioning and insulation for organs, and protects them from harm. A child’s body fat is determined by the proportion of fat in their body, not just their overall weight.

Muscle Mass and Bone Density

Muscle mass refers to the hard tissue responsible for movement, strength, growth, and calorie burning. Bone density helps support the body’s weight and protects vital organs like the brain and heart.

The Centers for Disease Control and Prevention (CDC) have established guidelines for healthy weight and body mass index (BMI) in children, aiming for them to fall within the Healthy Weight Zone if they are growing and developing normally.

Average weight of a 13-year-old boy

The average weight of a 13-year-old boy is typically between 75 and 145 pounds. If a boy’s weight is at the 50th percentile, it means that out of 100 boys his age, 50 will weigh more and 50 will weigh less. If his weight is at the 25th percentile, it means that 75 out of 100 boys will weigh more and 25 will weigh less.

Weight percentiles for 13-year-old boys:

5th percentile75 pounds
10th percentile80 pounds
25th percentile88 pounds
50th percentile100 pounds
75th percentile116 pounds
90th percentile133 pounds
95th percentile145 pounds

Average weight of a 13-year-old girl

The weight range for 13-year-old girls is typically between 76 and 148 pounds. Additionally, the average weight for girls of this age is around 101 pounds. When considering a group of 100 13-year-old girls, it can be observed that 50 of them would weigh more than 101 pounds, while the remaining 50 would weigh less.

Weight percentiles for 13-year-old girls:

5th percentile76 pounds
10th percentile80 pounds
25th percentile89 pounds
50th percentile101 pounds
75th percentile116 pounds
90th percentile135 pounds
95th percentile148 pounds

Healthy Weight For A 13-Year-Old

The healthy weight for a 13-year-old depends on their height, gender, and age. To determine if your child is at a healthy weight, the CDC uses a measurement called BMI, which stands for body mass index. You can find many online calculators to help you calculate your child’s BMI.

For a 13-year-old boy, weighing more than 85 pounds is considered unhealthy. Similarly, for a girl of the same age, weighing more than 95 pounds is considered unhealthy. These are general guidelines, and it’s important to consult with a healthcare professional for a comprehensive evaluation of your child’s health.

Here you can know more detail about Healthy and Effective Weight Loss Tips for Teenagers.

Factors that Actually Affect a Teenager’s Weight

Several factors can influence a teenager’s weight, including genetics, diet, exercise, and hormonal changes.


A child’s weight can be influenced by their genes. If parents are overweight or obese, their child may be more likely to struggle with weight due to how their body processes and stores fat.


The food a teenager eats plays a crucial role in weight management. A diet high in processed foods and sugary drinks, combined with a sedentary lifestyle, increases the risk of weight gain. Encouraging a healthy diet with fruits, vegetables, lean proteins, and whole grains is important for maintaining a healthy weight.


Regular physical activity is essential for weight control. Encourage your teenager to engage in activities like sports, walks, runs, or fitness classes. Exercise helps burn calories, build muscle mass, and boost metabolism, which aids in maintaining a healthy weight.

Hormonal Changes

Hormonal changes during puberty can impact weight. Increased production of insulin-like growth factor 1 (IGF-1) can lead to increased appetite and weight gain. However, these hormonal changes alone don’t contribute significantly to weight gain. A balanced diet and regular exercise can help manage weight during this time.

Understanding Body Mass Index (BMI)

Body mass index (BMI) is a useful measurement that considers more than just your weight. It calculates body fat percentage based on your height and weight, without needing complex methods like skinfold measurements.

For teenagers, BMI calculations also take into account their age and sex, known as “BMI-for-age.” This helps determine how your teenager’s BMI compares to others their age.

To calculate a child’s BMI, divide their weight in kilograms by their height in meters squared. If their BMI falls at or above the 85th percentile for children of the same age and sex, they may be considered overweight.

Keep in mind that BMI is just one way to assess body size and shape. It doesn’t consider factors like muscle mass or bone structure. For example, high-performance athletes may have BMIs that suggest overweight status by certain criteria, but they still fall within the normal range because they have more muscle mass.

Remember, BMI is a helpful tool, but it’s not the only factor to consider when evaluating your overall health.

Calculate Your BMI

The person’s weight in relation to their height is measured by BMI, which stands for Body Mass Index. To calculate BMI, the weight in kilograms is divided by the square of the height in meters (kg/m2). Different ranges of BMI have been categorized by the World Health Organization to indicate health risks for adults. These categories are based on the association between BMI values and potential health problems.

To calculate your BMI, divide your weight in kilograms by your height in meters squared (kg/m2).

Understanding BMI Categories:

BMI less than 18.5:
Falls within the healthy weight range
Recommended for children and teens ages 2 to 19

BMI between 18.5 and 24.9:
Healthy weight range
Recommended for children ages 2 to 19

BMI between 25 and 29.9:
At risk of overweight
Recommended for children ages 2 to 19

Weight Considerations for Children:

When evaluating your child’s health, weight is an important factor. The average weight for 13-year-olds is between 90-100 lbs. Girls tend to be taller than boys until they reach puberty.

What Are The Recommended Weights For Children?

The Centers for Disease Control and Prevention (CDC) suggests monitoring your child’s height and weight regularly, and here’s what you should know:

  • BMI 30 or higher: Obese; At risk of overweight
  • BMI 25-29.9: Overweight; At risk of overweight
  • BMI 18.5-24.9: Healthy weight range
  • BMI less than 18.5: Underweight

Percentiles By Weight For 13-Year-Old Girls

Here are the percentiles by weight for 13-year-old girls:


Percentiles By Weight For 13-Year-Old Boys

Here are the percentiles by weight for 13-year-old boys:


Teenage Girls & Boys Height


Why is my child’s weight important?

It’s important to pay attention to your child’s weight because gaining too much or losing too much can cause health problems in the future.


If your child is overweight or obese, they are at risk of developing type 2 diabetes, high cholesterol, and high blood pressure later in life. Even kids who are considered normal weight may still have a high BMI, which means they are also at risk for these conditions.

Cholesterol Problems

Cholesterol levels in the blood can indicate the likelihood of developing heart disease later in life. Children with high cholesterol levels may need medication to lower it, which can help prevent serious health issues in the future.

Factors That Affect Weight

Many things can influence a child’s weight, such as genes, surroundings, physical activity, and eating habits.
If your child’s BMI is at or above the 85th percentile for their age group, talk to your doctor about promoting healthy habits like eating well and exercising regularly to help them reach a healthy weight.


  • Children with parents who have a history of obesity or diabetes are more likely to become overweight.
  • If both parents are overweight or obese, their child is at a higher risk of becoming overweight.


  • Our surroundings promote unhealthy eating habits and limit opportunities for physical activity.
  • Many schools have reduced physical education classes, and students spend most of their day sitting in class rather than being active outside. This makes it harder for parents to teach healthy habits to their children.

Physical Activity Level

  • Only 1 in 4 children meet the recommended 60 minutes of daily physical activity.
  • Insufficient exercise can lead to more weight gain compared to regular physical activity through sports or dance classes.

Rate Of Development And Puberty

  • Children who develop earlier may weigh more than those who develop later.
  • Puberty can affect weight, especially for girls. Girls may gain 5 to 20 pounds during puberty, particularly if they have more body fat in their thighs and hips.


  • Some children have more muscle, which makes them weigh more.
  • Those who participate in sports or physical activities tend to have higher weights due to increased muscle mass.

Body Composition

  • The ratio of body fat to lean muscle affects a child’s weight and overall well-being.
  • If your child’s weight seems high compared to their height, consult a healthcare provider to address this concern.


  • As children grow older, they are more likely to gain body fat, regardless of gender or race.
  • Girls may experience increased fat deposits in the hips, thighs, buttocks, and breasts due to higher estrogen levels during puberty.

Exercise Levels

  • Physical activity plays a crucial role in determining if children are overweight.
  • Sedentary lifestyles increase the risk of obesity compared to regular physical activity.

Nutrition And Lifestyle Habits

  • Genetics and environment, including family habits, influence a child’s growth.
  • Factors like diet, sleep patterns, and physical activity can affect weight from adolescence into adulthood.

Family History

  • If family members are overweight or obese, the child is more likely to gain weight.
  • The risk of childhood obesity increases when one or both parents are overweight or obese, especially if the child consumes fast food and lacks regular exercise.


  • The age at which children enter puberty affects the amount of weight they gain during this period.
  • Early puberty can raise concerns about a child’s weight.

Average weight and height for 13-year-olds:

  • The average weight for a 13-year-old girl is approximately about 112 pounds (51 kg).
  • Boys tend to be taller and weigh more on average than girls at this age.
  • The average height for a 13-year-old boy is about 5 feet 3 inches (160 cm).

Growth differences:

  • Boys generally experience faster growth during adolescence than girls, especially between ages 10 and 14.
  • However, girls’ growth spurts tend to last longer due to their smaller starting size.

Tips for Maintaining a Healthy Weight

Maintaining a healthy weight is important for overall health and well-being.

Eat balanced meals

Encourage your teenager to have a diet that includes lots of fruits, veggies, lean proteins, and whole grains. Avoid processed foods or packaged food and sugary drinks that can easily lead to weight gain.

Stay active

Encourage regular physical activity like playing sports, going for walks or runs, or joining a dance or fitness class. This really helps burn calories, build muscle, and increase metabolism.

Limit screen time

Encourage your teenager to reduce time spent on screens and engage in other activities like reading, playing games, or going for a bike ride. Excessive screen time is linked to weight gain and other health problems.


Puberty brings physical changes and emotional challenges for teens. Averages and percentiles are important in considering obesity-related health issues during the teen years. Focus on your child’s body image and self-talk to promote positive self-esteem. If you have concerns about weight, development, or self-esteem, consult a pediatrician.

If your daughter is underweight, ensure she’s eating enough and not experiencing sudden weight loss. Consider consulting a doctor to rule out any underlying health problems.

BMI is a measurement, not a diagnostic tool. If your daughter is underweight, consult your GP for further recommendations.


How much should a 13-year-old weigh?

The average weight for a 13-year-old varies, but according to CDC, most girls weigh around 76-148 pounds and most boys weigh between 75-145 pounds. However, the weight can vary based on different factors.

Is it possible for a 13-year-old to weigh 70 pounds?

Yes, it is possible for a 13-year-old to weigh 70 pounds. However, the average weight for a 13-year-old boy is typically between 75 and 145 pounds, and for a girl, it’s nearly between 76 and 148 pounds. The 50th percentile weight for boys is around 100 pounds, and for girls, it’s around 101 pounds.

Is 13 a good age to start losing weight?

Yes, losing weight can be beneficial for individuals of all ages, including teenagers. Losing excess body fat can improve health, enhance self-esteem, and boost confidence. However, it’s crucial for teens to focus on healthy weight loss methods, such as making dietary and lifestyle changes that support their growing bodies and can be maintained in the long run.

Do you lose weight during puberty?

No, during puberty, most adolescents actually experience weight gain as they go through a growth spurt. Between the ages of 13 and 18, it’s common for teenagers to double their weight. However, this can be a sensitive topic for parents who worry about excessive weight gain happening too quickly.

Is it worse to be underweight or overweight?

According to recent research from CU Boulder, being overweight or obese significantly increases the risk of death, by anywhere from 22% to 91%. This risk is higher than previously believed. On the other hand, the mortality risk associated with being slightly underweight may have been overestimated.

Meet Flora Lambeth, an experienced freelance journalist with a rich portfolio featured in renowned publications such as Women’s Health, Men’s Health, and Woman’s Day. With a passion for infusing humanity into her writing, Flora excels in crafting authentic profiles and narratives. Her expertise lies in covering topics related to Health and Fitness.

Leave a Comment