1. What is Body Mass Index (BMI)?

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 a person's weight in kilograms divided by the square of their height in meters.

2. How Does the Calculator Work?

The calculator uses the BMI formula:

Where:

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

Explanation: The BMI provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems objectively with their patients.

3. Importance of BMI Calculation

Details: BMI is an inexpensive and easy screening method for weight category—underweight, healthy weight, overweight, and obesity. It correlates moderately well with direct measures of body fatness.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For pounds and inches, convert first (1 kg = 2.2 lbs, 1 m = 39.37 inches). All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

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

Q2: Is BMI different for men and women?
A: The calculation is the same, but healthy ranges may differ slightly due to body composition differences.

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

Q4: Is BMI accurate for everyone?
A: BMI may not be accurate for athletes, pregnant women, the elderly, or those with unusual body compositions.

Q5: Should children use this calculator?
A: No, children and teens need age- and sex-specific percentiles rather than fixed BMI categories.