Child & Teen BMI Calculator
Calculate and interpret Body Mass Index (BMI) percentiles for children and teenagers aged 2-20 years using CDC growth charts. This specialized calculator accounts for age and gender differences in body composition during growth.
BMI Results
Understanding Child & Teen BMI
Body Mass Index (BMI) for children and teens is calculated differently from adult BMI. Instead of using fixed BMI ranges, children's BMI is compared to other children of the same age and gender using percentiles from CDC growth charts.
BMI Percentile Categories
| 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 |
| Obese | 95th percentile or greater |
Why BMI Percentiles Matter
BMI percentiles are essential for several reasons:
- Account for normal differences in body fat between boys and girls
- Consider age-related changes in body composition during growth
- Provide a reliable indicator of body fatness for most children and teens
- Help identify potential weight issues early
Limitations of BMI
While BMI is a useful screening tool, it has some limitations:
- Does not directly measure body fat
- May not be accurate for very athletic children
- Should be part of a broader health assessment
- May need adjustment for certain ethnic groups
When to Be Concerned
Consider consulting a healthcare provider if:
- BMI is below the 5th percentile
- BMI is at or above the 95th percentile
- There are rapid changes in BMI percentile
- Other health concerns are present
Factors Affecting BMI in Children
Several factors can influence a child's BMI:
- Genetics and family history
- Diet and nutrition
- Physical activity levels
- Sleep patterns
- Medical conditions
- Medications
Using This Calculator
For accurate results:
- Enter the child's exact age in years
- Select the correct gender
- Input precise height and weight measurements
- Use recent measurements (within the last month)
- Track BMI changes over time
Note: This calculator uses the CDC Growth Charts for children and teens aged 2-20 years in the United States. Different growth charts may be more appropriate for other populations.