1. What is BMI?

Definition: Body Mass Index (BMI) is a value derived from the mass (weight) and height of a person.

Purpose: The BMI is a simple, widely-used method to classify weight status and identify potential weight problems in adults.

2. How Does the BMI Calculator Work?

The calculator uses the formula:

Where:

• \( BMI \) — Body Mass Index (kg/m²)
• \( W \) — Weight (kilograms)
• \( H \) — Height (meters)

Explanation: Your weight in kilograms is divided by the square of your height in meters.

3. BMI Categories (UK Standard)

Details:

• Underweight: BMI less than 18.5
• Normal weight: BMI 18.5 to 24.9
• Overweight: BMI 25 to 29.9
• Obese: BMI 30 or greater

4. Using the Calculator

Tips: Enter your weight in kilograms and height in meters. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Is BMI accurate for everyone?
A: BMI may not be accurate for athletes (high muscle mass), pregnant women, or the elderly as it doesn't distinguish between muscle and fat.

Q2: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy.

Q3: Should children use this calculator?
A: No, children and teens need age and sex-specific BMI charts.

Q4: How often should I check my BMI?
A: Periodic checks (every few months) can help track weight changes.

Q5: Where can I get more health advice?
A: Consult your GP or visit NHS website for UK-specific health guidance.