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 a person's weight in kilograms divided by the square of their 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 height squared, providing a standardized measure across different heights.

3. Importance of BMI Calculation

Details: BMI provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems objectively with their patients. 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 not accurately reflect body fat in athletes (high muscle mass), elderly (muscle loss), or certain ethnic groups.

Q3: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy, though individual factors should be considered.

Q4: Should children use this calculator?
A: No, children and teens need age- and sex-specific BMI percentiles rather than these adult categories.

Q5: What are alternatives to BMI?
A: Waist circumference, waist-to-hip ratio, or body fat percentage measurements may provide additional information.