BMI Calculator for Teens
A tool for teens to calculate their BMI and understand it in the context of growth, puberty, and percentile charts for a healthy assessment.
A Guide to BMI for Teenagers
Calculating Body Mass Index (BMI) for teenagers is the same as for adults, but interpreting the result requires a different approach. During the teenage years, bodies are undergoing rapid changes in height, weight, and body composition due to puberty. Because of this, a teen's BMI must be compared to others of the same age and sex.
Why BMI Percentiles are Used for Teens
Instead of the fixed categories used for adults, healthcare providers use BMI-for-age percentile charts (from organizations like the WHO or CDC) to assess a teen's weight status. This approach compares a teen's BMI with the average BMI of other American teens of the same age and sex.
For example, if a teenage boy is in the 75th percentile, it means his BMI is higher than 75% of other boys his age.
📊 General BMI-for-Age Categories
Here are the general categories used by the CDC and pediatricians based on percentile:
| Weight Status Category | Percentile Range |
|---|---|
| Underweight | Less than the 5th percentile |
| Healthy weight | 5th percentile to less than the 85th percentile |
| Overweight | 85th to less than the 95th percentile |
| Obesity | Equal to or greater than the 95th percentile |
This calculator provides the BMI number itself. The result is intentionally labeled 'Requires Percentile Chart' because only a healthcare provider can accurately plot this number on a growth chart to determine the correct percentile and weight status.
Important Considerations for Teens
- Puberty and Growth Spurts: Teens grow at different rates. It's normal to gain weight before a growth spurt in height. This can temporarily lead to a higher BMI that resolves as height catches up.
- Body Composition: Like adults, BMI doesn't distinguish muscle from fat. Teen athletes may have a high BMI due to muscle mass.
- Focus on Healthy Habits: Rather than focusing solely on the number, it's more productive to focus on healthy habits like eating a balanced diet, getting regular physical activity, and ensuring adequate sleep.
Disclaimer: This tool is for informational purposes only. It is not a substitute for professional medical advice. If you have concerns about a teenager's weight or health, please consult a healthcare provider.