BMI Calculator for Teens
Adolescents experience rapid growth. Use this calculator to obtain BMI and then compare it with BMI-for-age percentiles for teens.
Results
BMI
23.0
Next step
Reference CDC/WHO BMI-for-age charts for boys aged 16 to determine weight status.
Converted values: Height 172.0 cm • Weight 68.0 kg
How to Use This Calculator
Measure accurately
Use a stadiometer or wall ruler for height and a calibrated scale for weight. Enter numbers in your preferred unit system.
Record age and sex
BMI-for-age percentiles differ by sex. Accurate age (in years and months) improves percentile lookup accuracy.
Use growth charts
Compare the BMI result against CDC or WHO percentile charts to classify underweight, healthy weight, overweight, or obesity.
Formula
BMI = Weight ÷ Height²
- Metric: weight (kg) ÷ height² (m²)
- Imperial: weight (lb) ÷ height² (in²) × 703
- Translate BMI to a percentile using age- and sex-specific charts for teens.
Full Description
During adolescence, BMI alone is not diagnostic because growth spurts and puberty influence body composition. Use BMI alongside percentiles, waist measurements, and activity assessments to build a full picture of teen health.
Typical percentile categories: <5th (underweight), 5th–85th (healthy weight), 85th–95th (overweight), and ≥95th (obesity). Seek guidance from a pediatric healthcare provider before making major nutrition or training changes.
Frequently Asked Questions
How do I convert BMI to a percentile?
Use official CDC or WHO growth charts. Plot BMI against age (in months) for the appropriate sex to find the percentile.
Should athletes worry about BMI?
Athletic teens might have higher BMI due to muscle mass. Combine BMI with body composition assessments and performance metrics.
Can BMI predict health issues?
High BMI percentiles correlate with metabolic risk factors, but an individualized evaluation is essential before drawing conclusions.
How frequently should teens measure BMI?
Twice per year is sufficient unless a healthcare provider requests more frequent monitoring.