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

5. Frequently Asked Questions (FAQ)

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

Q2: Are there limitations to BMI?
A: BMI doesn't distinguish between muscle and fat, so athletes may have high BMI without excess fat. It may underestimate body fat in older people.

Q3: Is BMI different for children?
A: Yes, children's BMI is age and sex-specific and is referred to as BMI-for-age percentile.

Q4: What's a healthy BMI for older adults?
A: Some studies suggest 23-27 may be optimal for those over 65, rather than the standard 18.5-24.9.

Q5: Should BMI be the only measure of healthy weight?
A: No, waist circumference and other risk factors should also be considered for a complete assessment.