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: The formula correlates reasonably well with body fat percentage for most people, though it doesn't directly measure body fat.

3. Importance of BMI Calculation

Details: BMI is used to screen for weight categories that may lead to health problems. It's a useful population-level measure of overweight and obesity.

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).

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, multiply weight (lbs) by 703, divide by height (inches) squared.

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

Q5: Should children use this calculator?
A: No, children and teens need age- and sex-specific percentiles rather than the adult categories.