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BMI Formula:
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Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, overweight and obesity in adults and teenagers. It is defined as a person's weight in kilograms divided by the square of their height in meters (kg/m²).
The calculator uses the BMI formula:
Where:
Explanation: The formula calculates body mass index by dividing weight by the square of height, providing a standardized measurement of body composition.
Details: BMI is a simple, non-invasive screening tool that helps identify potential weight problems in teenagers. It's an important indicator of health risks associated with being underweight, overweight, or obese.
Tips: Enter weight in kilograms and height in meters. All values must be valid (weight > 0, height > 0). For accurate results, measure weight and height using standardized methods.
Q1: What are the BMI categories for teenagers?
A: For teenagers, BMI is interpreted using age- and sex-specific percentiles rather than the standard adult categories.
Q2: Why is BMI interpretation different for teenagers?
A: Teenagers' body composition varies by age and sex as they grow, so BMI must be compared to growth charts specific to their age and gender.
Q3: What are the limitations of BMI for teenagers?
A: BMI doesn't distinguish between muscle and fat mass, so athletic teenagers with more muscle may have a higher BMI that doesn't reflect excess body fat.
Q4: How often should teenagers calculate their BMI?
A: Healthcare providers typically track BMI during annual checkups. Frequent self-monitoring isn't recommended as it may lead to unhealthy focus on weight.
Q5: Where can I find BMI percentile charts for teenagers?
A: The CDC provides growth charts that include BMI-for-age percentiles for children and teenagers aged 2-20 years.