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 calculated by dividing weight in kilograms by the square of height in meters.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

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

3. Importance of BMI Calculation

Details: BMI is an inexpensive and easy screening method for weight category—underweight, healthy weight, overweight, and obesity. For most people, BMI correlates with amount of body fat.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. All values must be valid (weight > 0, height > 0). For most accurate results, measure height without shoes and weight in light clothing.

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), Obesity (≥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: How often should I check my BMI?
A: For most adults, checking BMI once a year is sufficient unless you're actively trying to lose or gain weight.

Q4: Are there different BMI standards for men?
A: The same BMI categories apply to both men and women, though men tend to have more muscle mass at a given BMI.

Q5: Why focus on men in Australia and New Zealand?
A: While BMI calculations are universal, this calculator provides interpretation specific to male populations in Australia and New Zealand.