1. What is BMI?

BMI (Body Mass Index) is a simple calculation using a person's height and weight to screen for weight categories that may lead to health problems. It provides a reliable indicator of body fatness for most people.

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 divides weight by the square of height to account for the relationship between height and body surface area.

3. Importance of BMI Calculation

Details: BMI is used to identify possible weight problems in adults. While it doesn't measure body fat directly, research has shown it correlates with direct measures 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 UK metric measurements, use kilograms and meters.

5. Frequently Asked Questions (FAQ)

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

Q2: Is BMI accurate for everyone?
A: BMI may overestimate body fat in athletes and underestimate it in older people who have lost muscle mass.

Q3: How often should I check my BMI?
A: Periodic checks are sufficient unless you're actively trying to lose or gain weight.

Q4: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy.

Q5: Should children use this calculator?
A: No, children and teens need age- and sex-specific BMI percentiles.