Boys BMI chart in cms and kgs for Teenagers 13 years old

BMI chart for 13-Year-Old boys

What the BMI percentile chart shows for teenage boys at 13-Year-Old.

BMI percentiles for 13-Year-Old boys

Based on CDC and WHO reference data, BMI percentiles for teenage boys at 13-Year-Old are:

• 5th percentile (underweight threshold): 15.4

• 25th percentile: 17.0

• 50th percentile (median): 18.4

• 75th percentile: 20.4

• 85th percentile (overweight threshold): 21.8

• 95th percentile (obesity threshold): 25.1

The percentile values on this page are displayed in cm and kg.

The CDC classifies BMI-for-age percentiles for teenage boys as follows: underweight below the 5th percentile, healthy weight between the 5th and 85th percentiles, overweight between the 85th and 95th percentiles, and obese above the 95th percentile.

A percentile ranking tells you where their measurement falls among teenage boys of the same age. The 50th percentile is the statistical midpoint of the population.

BMI and development for teenage boys

At 13, BMI continues to be assessed using the age-specific CDC percentile chart rather than the adult categories used from age 18. During puberty, body composition changes mean that raw BMI values are less meaningful in isolation. Most 13-year-olds with a BMI between the 5th and 85th percentile for their age and sex are considered to have a healthy weight.

BMI during puberty: what to know

For teenagers, BMI-for-age percentile is assessed in the context of puberty stage, which significantly affects weight and body composition independently of health behaviours. A temporary rise in BMI percentile during puberty is common and does not automatically indicate unhealthy weight gain.

Healthy behaviours to support BMI in teenagers

Regular physical activity (60 minutes daily), adequate sleep (8-10 hours), and a balanced diet that does not restrict any major food group are the evidence-based supports. Restrictive dieting in adolescence is associated with poorer long-term outcomes for both weight and mental health.

Body image and eating concerns

Adolescents are at increased vulnerability to body image concerns and eating disorders. Any significant restriction of food intake, purging, or intense preoccupation with body weight warrants sensitive discussion and, where needed, early referral to a specialist. Earlier intervention leads to substantially better outcomes.

Frequently asked questions

Does puberty affect BMI percentile?

Yes - puberty causes significant changes in body composition, including increases in both fat mass and muscle mass, that affect BMI independently of health behaviours. A temporary rise in BMI percentile during the pubertal growth phase is common and expected. The age- and sex-specific CDC percentile chart accounts for these changes, which is why it is used rather than adult BMI categories for teenagers.

What is a healthy BMI for teenagers?

For teenagers, a healthy BMI-for-age falls between the 5th and 85th percentile on the CDC chart. The actual BMI number that corresponds to these percentiles changes with age - for example, a BMI of 22 might be at the 85th percentile for a 10-year-old but completely within the normal range for a 17-year-old. This is why the chart is essential and absolute numbers alone are not meaningful for this age group.

Should teenagers monitor their BMI?

Teenagers do not need to routinely monitor their own BMI at home. Regular check-ups with a GP or school health nurse provide the appropriate context for growth assessment. Frequent self-monitoring of weight or BMI by teenagers is associated with increased body dissatisfaction and risk of disordered eating. If a concern exists, assessment by a healthcare professional provides a much more complete and contextually appropriate evaluation.

Data sources and methodology

The percentile ranges on this page are drawn from CDC growth chart data from the National Center for Health Statistics and WHO Child Growth Standards (for children under 5). CDC data published May 30, 2000, with 2022 extended BMI tables. Percentiles are modelled using the LMS method (Box-Cox transformation), which accounts for the skewed distribution of measurements at each age. All measurements are given in metric units with imperial equivalents.

For personalised guidance, consult a paediatrician or healthcare provider who can assess their measurements in the context of their full growth history.