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 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 standard BMI formula:

Where:

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

Explanation: The formula calculates body mass per unit of height squared, providing a standardized measure of body composition.

3. Importance of BMI Calculation

Details: BMI is a simple screening tool for weight categories that may lead to health problems. For Australian adults in 2019, BMI classifications were particularly important for assessing obesity trends and associated health risks.

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 BMI categories for Australian adults?
A: Underweight (<18.5), Normal weight (18.5-24.9), Overweight (25-29.9), Obese (≥30).

Q2: Does BMI interpretation change with age?
A: Yes, for older adults, the healthy BMI range may be slightly higher (up to 27).

Q3: What were the 2019 Australian BMI statistics?
A: In 2019, approximately 67% of Australian adults were overweight or obese according to BMI measurements.

Q4: Are there limitations to BMI?
A: BMI doesn't distinguish between muscle and fat mass, and may not be accurate for athletes, pregnant women, or certain ethnic groups.

Q5: Should children use this calculator?
A: No, children and adolescents require age- and sex-specific BMI percentiles rather than adult categories.