Children’s BMI Calculator & Growth Tool
Instantly calculate your child’s Body Mass Index (BMI) based on age, gender, height, and weight. A free, reliable screening tool for parents and caregivers.
Calculate Your Child’s BMI
Enter your child’s details below to get an instant BMI calculation and general health category based on standard pediatric guidelines.
Child’s Details
Accurate measurements ensure the most reliable BMI estimate
BMI Results
Calculated health metrics and interpretation
Pediatric BMI Categories
Unlike adults, children’s BMI is evaluated using age and sex-specific percentiles. Here is how healthcare providers interpret the results.
| BMI Percentile | Weight Status Category | General Guidance |
|---|---|---|
| Less than 5th percentile | Underweight | May indicate insufficient nutrition or underlying health conditions. Consult a pediatrician. |
| 5th to less than 85th percentile | Healthy Weight | Indicates a healthy weight relative to age and height. Maintain balanced diet and active lifestyle. |
| 85th to less than 95th percentile | Overweight | Higher risk for weight-related issues. Focus on healthy eating habits and increased physical activity. |
| 95th percentile or greater | Obese | Significantly higher health risks. Professional medical guidance and a structured health plan are recommended. |
Children’s BMI Calculator FAQ
Everything you need to know about calculating and understanding Body Mass Index for children and teens.
BMI for children is calculated using the same mathematical formula as adults: weight (kg) divided by height (m) squared. However, the result is interpreted differently using age and sex-specific percentiles from CDC or WHO growth charts, rather than fixed number ranges.
A healthy BMI for a child typically falls between the 5th and 84th percentiles for their specific age and gender. Below the 5th percentile is considered underweight, 85th to 94th is overweight, and 95th or higher is considered obese.
BMI can be reliably calculated and tracked for children starting at age 2. For infants and toddlers under 2 years old, healthcare providers use weight-for-length percentiles instead of BMI.
No. This calculator provides a general screening estimate. Because children’s bodies change rapidly during growth spurts, only a pediatrician can provide an accurate health assessment using official growth charts and a comprehensive medical evaluation.