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BMI Formula:
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Body Mass Index (BMI) is a measure of body fat based on height and weight that applies to both adult men and women. For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age.
The calculator uses the BMI formula:
Where:
Explanation: BMI provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems more objectively with their patients.
Details: BMI is an inexpensive and easy screening method for weight category—underweight, healthy weight, overweight, and obesity. For children, BMI percentiles are the most commonly used indicator to assess the size and growth patterns of individual children.
Tips: Enter weight in kilograms and height in meters. All values must be valid (weight > 0, height > 0). For children, the BMI number should be plotted on a BMI-for-age growth chart.
Q1: Why use BMI for children?
A: BMI-for-age is the recommended measure to screen for overweight and obesity in children because it takes into account normal differences in body fat between boys and girls and differences in body fat at various ages.
Q2: What are healthy BMI ranges for children?
A: Unlike adults, BMI numbers for children are compared against growth charts for children of the same age and sex. A child between the 5th and 85th percentile is considered a healthy weight.
Q3: When should BMI be measured in children?
A: The American Academy of Pediatrics recommends BMI screening at least annually for all children and adolescents.
Q4: Are there limitations to BMI?
A: BMI doesn't directly measure body fat and doesn't account for factors like muscle mass, bone density, or overall body composition. It's just one indicator among many to consider when evaluating a child's health.
Q5: What should I do if my child's BMI is high?
A: Consult with your pediatrician or healthcare provider who can perform further assessments and help develop a healthy weight management plan if needed.