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BMI Formula:
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Body Mass Index (BMI) is a simple calculation using a person's height and weight. The formula is BMI = kg/m² where kg is a person's weight in kilograms and m² is their height in meters squared. It provides a reliable indicator of body fatness for most people.
The calculator uses the standard BMI formula:
Where:
Explanation: The formula divides a person's weight by the square of their height to categorize them into underweight, normal weight, overweight, or obese categories.
Details: BMI is a simple, inexpensive screening method for weight category—underweight, healthy weight, overweight, and obesity. It correlates with direct measures of body fat and is strongly associated with various metabolic and disease outcomes.
Tips: Enter weight in kilograms, height in meters, and optionally age. All values must be valid (weight > 0, height > 0). For Blue Zone analysis, age helps determine optimal BMI ranges for longevity.
Q1: What is a healthy BMI range for Blue Zones?
A: In longevity Blue Zones, most men maintain a BMI between 18.5-25, with slight variations by age. Older adults often have slightly higher optimal BMI ranges.
Q2: Does BMI differ by age for men?
A: Yes, optimal BMI ranges may increase slightly with age. For men over 65, a BMI of 23-27 may be healthier than the standard 18.5-25 range.
Q3: What are the limitations of BMI?
A: BMI doesn't distinguish between muscle and fat, so muscular individuals may be misclassified. It also doesn't account for fat distribution.
Q4: How does BMI relate to longevity in Blue Zones?
A: Blue Zone populations typically maintain BMIs in the lower normal range (20-23) throughout most of adulthood, supporting longevity.
Q5: Should athletes use BMI?
A: Highly muscular athletes may have high BMIs without excess fat. Additional measures like waist circumference may be more appropriate.