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 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 equation:

Where:

• \( weight \) — Weight in kilograms (kg)
• \( height \) — Height in meters (m)

Explanation: The equation provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems more objectively with their patients.

3. Importance of BMI Calculation

Details: BMI provides the most useful population-level measure of overweight and obesity as it is the same for both sexes and for all ages of adults. However, it should be considered a rough guide because it may not correspond to the same degree of fatness in different individuals.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For height, you can convert from cm to m by dividing by 100 (e.g., 175 cm = 1.75 m).

5. Frequently Asked Questions (FAQ)

Q1: What are the 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 be accurate for athletes (muscle weighs more than fat), pregnant women, or the elderly.

Q3: What is a healthy BMI range in Australia?
A: For most adults, a healthy BMI is between 18.5 and 24.9 according to Australian health standards.

Q4: Should children use this calculator?
A: No, children and teens need age- and sex-specific BMI calculations due to growing bodies.

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