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 for comparing individuals of 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 more 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, height in meters, and age in years. All values must be valid (weight > 0, height > 0, age between 1-120).

5. Frequently Asked Questions (FAQ)

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

Q2: Does BMI differ for women?
A: The same BMI categories apply to both men and women, though women typically have more body fat than men at the same BMI.

Q3: How does age affect BMI?
A: BMI may overestimate body fat in older people who have lost muscle mass, and underestimate it in younger people with more muscle.

Q4: Are there limitations to BMI?
A: BMI doesn't account for muscle mass, bone density, overall body composition, or racial and sex differences.

Q5: Is BMI accurate for athletes?
A: BMI may classify muscular athletes as overweight or obese even when they have low body fat.