1. What is BMI?

Body Mass Index (BMI) is a person's weight in kilograms divided by the square of height in meters. BMI is an inexpensive and easy screening method for weight category—underweight, healthy weight, overweight, and obesity.

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 more objectively with their patients.

3. Importance of BMI Calculation

Details: BMI is used to screen for weight categories that may lead to health problems but it is not diagnostic of body fatness or health of an individual. It's a useful starting point for important conversations about weight between patients and healthcare providers.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For pounds and inches, convert first (1 kg = 2.2 lbs, 1 m = 39.37 inches). All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

Q1: What are the BMI categories for adults?
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 persons who have lost muscle mass.

Q3: Why use metric units?
A: The standard BMI formula uses kg/m². For imperial units, the formula is [weight (lbs) / height² (in)] × 703.

Q4: Does BMI apply to children?
A: For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age.

Q5: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy, though individual factors should be considered.