Child BMI Calculator
Calculate your child's Body Mass Index (BMI) and percentile based on CDC growth charts. This calculator is for children and teens aged 2 through 19 years.
Your Child's Results
Age: 5 years 0 months
Gender: Male
Height: 110 cm
Weight: 20 kg
BMI: 16.5
Percentile: 45th
Category: Healthy weight
BMI Categories for Children and Teens
| BMI Percentile | Weight Status |
|---|---|
| Less than 5th | Underweight |
| 5th to less than 85th | Healthy weight |
| 85th to less than 95th | Overweight |
| 95th and above | Obese |
About Child BMI Calculator
Body Mass Index (BMI) is a person's weight in kilograms divided by the square of height in meters. For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age.
How to Calculate Child BMI
BMI is calculated the same way for children as for adults, but the results are interpreted differently. The calculation is based on the following formulas:
Metric Units:
BMI = weight (kg) / (height (m))2
US Units:
BMI = 703 × weight (lb) / (height (in))2
BMI Percentiles for Children
For children and teens, BMI is not interpreted using standard weight status categories as it is for adults. Instead, BMI is compared to other children of the same age and sex using CDC growth charts.
Why BMI Percentile Matters
A high BMI percentile for age and sex may indicate high body fatness, while a low BMI percentile may indicate undernutrition. However, BMI is not a direct measure of body fatness and should be interpreted by a healthcare provider.
Limitations of BMI for Children
BMI is a useful screening tool but it is not a diagnostic tool. A healthcare provider would need to perform further assessments to determine if excess fat is a problem. BMI doesn't distinguish between fat and muscle, so athletic children may have a high BMI without excess fat.