1. What is BMI?

Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, overweight and obesity in adults. It provides a reliable indicator of body fatness for most people.

2. How is BMI Calculated?

The calculator uses the standard BMI formula:

Where:

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

3. BMI Categories

Classification:

• Underweight: BMI < 18.5
• Normal weight: BMI 18.5-24.9
• Overweight: BMI 25-29.9
• Obesity: BMI ≥ 30

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).

5. Frequently Asked Questions (FAQ)

Q1: Is BMI accurate for everyone?
A: BMI may overestimate body fat in athletes and underestimate it in older people who have lost muscle mass.

Q2: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy.

Q3: Should children use this calculator?
A: No, children need age- and sex-specific BMI percentiles.

Q4: How often should I check my BMI?
A: Periodic checks (every few months) are sufficient unless making significant lifestyle changes.

Q5: What's better than BMI for health assessment?
A: Waist circumference and body fat percentage provide additional useful information.