Pediatric BMI Calculator
Assess your child's Body Mass Index relative to age and gender standards.
Calculated BMI
Note: For children, BMI is interpreted using age and sex-specific percentiles.
Understanding Pediatric Body Mass Index (BMI)
Body Mass Index (BMI) is a screening tool used to identify potential weight problems in children and adolescents. Unlike adult BMI, which uses fixed categories, a child's BMI must be interpreted relative to other children of the same age and biological sex. This is because the amount of body fat changes with age and differs between boys and girls.
How is Pediatric BMI Calculated?
The math behind the BMI value is the same for children and adults: Weight in kilograms divided by the square of height in meters. However, once the number is calculated, it is plotted on CDC growth charts to determine a percentile ranking.
A 10-year-old boy named Leo weighs 35 kg and is 140 cm tall (1.4 meters).
Calculation: 35 / (1.4 * 1.4) = 17.9 BMI.
On a growth chart, a BMI of 17.9 for a 10-year-old boy falls around the 65th percentile, which is considered a "Healthy Weight."
BMI Categories for Children (2 to 20 years)
- Underweight: BMI less than the 5th percentile.
- Healthy Weight: BMI from the 5th percentile to less than the 85th percentile.
- Overweight: BMI from the 85th percentile to less than the 95th percentile.
- Obesity: BMI at or above the 95th percentile.
Why Use a Pediatric BMI Calculator?
Early screening is crucial for long-term health. Pediatric BMI helps healthcare providers monitor growth patterns over time. If a child's BMI moves into the overweight or obese range, it may increase the risk of developing conditions like Type 2 diabetes, high blood pressure, and high cholesterol earlier in life.
Limitations of BMI
It is important to remember that BMI is a screening tool, not a diagnostic one. It does not measure body fat directly. For example, a very muscular child might have a high BMI but not high body fat. Always consult with a pediatrician for a full assessment of your child's health and growth.
Frequently Asked Questions
At what age can you start using BMI? BMI calculations are generally used for children and teens aged 2 through 19. For infants under 2, doctors use weight-for-length charts.
Does a high BMI mean my child is unhealthy? Not necessarily. It serves as a "red flag" for further evaluation by a medical professional who will look at diet, physical activity, and family history.