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 the weight in kilograms divided by the square of the height in meters (kg/m²).

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 formula calculates body mass per unit of surface area, providing a standardized measure for comparing individuals of different heights.

3. Importance of BMI Calculation

Details: BMI provides a useful population-level measure of overweight and obesity. It is used to screen for weight categories that may lead to health problems.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For height in centimeters, divide by 100 (e.g., 175 cm = 1.75 m). All values must be valid (weight > 0, height > 0).

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), Obese (≥30).

Q2: Is BMI accurate for everyone?
A: BMI may overestimate body fat in athletes and underestimate it in older persons who have lost muscle mass.

Q3: What are the limitations of BMI?
A: BMI doesn't account for muscle mass, bone density, overall body composition, or racial and sex differences.

Q4: Should BMI be used alone to diagnose obesity?
A: No, BMI should be used as a screening tool but not as a diagnostic tool. Other measures like waist circumference should also be considered.

Q5: How often should BMI be calculated?
A: For most adults, checking BMI annually is sufficient unless there are significant weight changes.