The Child BMI Calculator determines your child’s Body Mass Index (BMI) and compares it to CDC growth standards to calculate their BMI-for-age percentile.
Why BMI Matters for Children
Unlike adults, a child’s BMI must be interpreted relative to their age and sex because body composition changes as children grow. BMI-for-age percentiles provide a standardized way to assess whether a child’s weight is appropriate for their height and age.
BMI Categories for Children
- Underweight: Less than 5th percentile
- Healthy Weight: 5th to 84th percentile
- Overweight: 85th to 94th percentile
- Obese: 95th percentile or higher
Important Considerations
BMI is a screening tool, not a diagnostic tool. Several factors affect interpretation:
- Muscle mass (athletic children may have higher BMI)
- Growth patterns and puberty timing
- Family history and genetics
- Overall health and development
Note: This calculator is for educational purposes and screening only. It does not replace professional medical evaluation. Always discuss your child’s weight and health with their pediatrician.
What This Means
BMI (Body Mass Index) for children is interpreted differently than for adults because children's body composition changes as they grow and develop. Here's what your results mean:
Understanding the Categories:
- Underweight (< 5th percentile): May indicate inadequate nutrition or underlying health issues. Consult your pediatrician.
- Healthy Weight (5th-84th percentile): Your child's weight is appropriate for their height and age. Maintain healthy habits.
- Overweight (85th-94th percentile): Your child may be at risk for health problems. Discuss healthy lifestyle changes with your pediatrician.
- Obese (≥ 95th percentile): Higher risk for health issues like diabetes, high blood pressure, and joint problems. Medical evaluation and lifestyle interventions recommended.
Important Factors:
- BMI doesn't directly measure body fat
- Muscular or athletic children may have higher BMI
- Growth spurts can temporarily affect BMI
- Family history and genetics play a role
- Puberty timing affects body composition
Next Steps:
If your child's BMI is outside the healthy range, work with your pediatrician to:
- Rule out underlying medical conditions
- Assess overall health and development
- Create an age-appropriate nutrition and activity plan
- Set realistic, healthy goals
Remember: Focus on healthy behaviors, not just numbers. Encourage nutritious eating, regular physical activity, adequate sleep, and positive body image.