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BMI Formula for Children:
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Body Mass Index (BMI) is a screening tool that assesses weight relative to height. For children, BMI is age- and sex-specific and is referred to as "BMI-for-age" because their body composition varies as they grow.
The calculator uses the standard BMI formula adjusted for children:
Where:
Note: For children, the raw BMI number must be plotted on gender-specific growth charts to determine the BMI percentile.
Details: BMI-for-age is the recommended measure for screening overweight and obesity in children aged 2-20 years. It helps identify potential weight problems that may lead to health issues.
Tips: Enter weight in pounds, height in inches, exact age in years, and gender. For accurate results, measurements should be taken with minimal clothing and no shoes.
Q1: Why is BMI different for children than adults?
A: Children's body fat changes with age and differs between boys and girls, so BMI must be interpreted relative to other children of the same age and sex.
Q2: What is a healthy BMI for my child?
A: Healthy BMI ranges vary by age and gender. Generally:
Q3: When should I be concerned about my child's BMI?
A: Consult a pediatrician if your child is below the 5th percentile or at/above the 85th percentile, or if there are sudden changes in BMI percentile.
Q4: Are there limitations to BMI for children?
A: BMI doesn't distinguish between fat and muscle mass. Athletic children may have high BMI due to muscle rather than fat. Other assessments may be needed.
Q5: How often should my child's BMI be checked?
A: The American Academy of Pediatrics recommends BMI screening annually starting at age 2.