1. What is BMI?

Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, normal weight, overweight and obesity in adults. It is defined as weight in kilograms divided by the square of height in meters.

2. How Does the Calculator Work?

The calculator uses the BMI formula:

Where:

• \( weight \) — Body weight in kilograms
• \( height \) — Height in meters

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.

3. Importance of BMI Calculation

Details: BMI is a simple, inexpensive screening method for weight category - underweight, healthy weight, overweight, and obesity. While BMI doesn't measure body fat directly, research has shown that BMI correlates to direct measures of body fat.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, and age in years. All values must be valid (weight > 0, height > 0). For children and teens, BMI interpretation is age and sex-specific.

5. Frequently Asked Questions (FAQ)

Q1: What are the standard BMI categories for adults?
A: Underweight (<18.5), Normal weight (18.5-24.9), Overweight (25-29.9), Obese (≥30).

Q2: Is BMI interpretation different for children?
A: Yes, children's BMI is plotted on growth charts to determine percentiles based on age and sex.

Q3: What are limitations of BMI?
A: BMI doesn't distinguish between muscle and fat mass, so athletes may have high BMI without excess fat. It also doesn't account for fat distribution.

Q4: How often should BMI be calculated?
A: For adults, annual measurement is reasonable. For children, more frequent monitoring may be needed during growth spurts.

Q5: Are there better measures than BMI?
A: Waist circumference, skinfold thickness, and more advanced techniques like DEXA scans can provide more precise body composition analysis.