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 calculated by dividing a person's weight in kilograms by the square of their height in meters.

2. How Does the Calculator Work?

The calculator uses the BMI formula:

Where:

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

Example: For a person weighing 70 kg with height 1.75 m:
70 / (1.75 × 1.75) = 22.86 kg/m²

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.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

Q1: What are the BMI categories?
A: Underweight (<18.5), Normal (18.5-24.9), Overweight (25-29.9), Obesity (≥30)

Q2: Is BMI accurate for everyone?
A: BMI may not accurately reflect body fat in athletes (high muscle mass) or elderly (loss of muscle mass).

Q3: Should children use this calculator?
A: No, children and teens need age- and sex-specific percentiles rather than adult BMI categories.

Q4: What's better than BMI?
A: Waist circumference or body fat percentage measurements may provide better health risk assessment.

Q5: How often should I check my BMI?
A: For most adults, checking every few months is sufficient unless undergoing significant weight changes.