1. What is BMI?

BMI (Body Mass Index) is a measure that uses your height and weight to determine if your weight is healthy. It's widely used by healthcare professionals, including the NHS, to assess weight categories that may lead to health problems.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Explanation: The formula divides your weight by the square of your height to give a standardized measure of body weight relative to height.

3. Importance of BMI Calculation

Details: BMI helps identify potential weight problems in adults. While not a direct measure of body fat, it correlates with more direct measures and can indicate health risks associated with being underweight, overweight, or obese.

4. Using the Calculator

Tips: Enter your weight in kilograms and height in meters. For accuracy, measure your height without shoes and weight with minimal clothing. All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

Q1: What are the NHS BMI categories?
A: Underweight (below 18.5), Healthy weight (18.5-24.9), Overweight (25-29.9), Obese (30 and above).

Q2: Is BMI accurate for everyone?
A: BMI may not be accurate for athletes (high muscle mass), pregnant women, or those with unusual body compositions.

Q3: How often should I check my BMI?
A: For most adults, checking every few months is sufficient unless you're actively trying to change your weight.

Q4: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy, though this may vary slightly by ethnicity.

Q5: Should children use this calculator?
A: No, children need special BMI calculators that account for age and sex-specific growth patterns.