1. What is Body Mass Index (BMI)?

BMI is a simple index of weight-for-height that is commonly used to classify underweight, overweight and obesity in adults. It is defined as a person's weight in kilograms divided by the square of their height in meters (kg/m²).

2. How Does the Calculator Work?

The calculator uses the BMI formula:

Where:

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

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 a simple, inexpensive, and noninvasive surrogate measure of body fat. It correlates moderately well with direct measures of body fat and is used to screen for weight categories that may lead to health problems.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. All values must be valid (weight > 0, height > 0). 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 standard BMI categories?
A: Underweight (<18.5), Normal weight (18.5-24.9), Overweight (25-29.9), Obesity (≥30).

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

Q3: Should children use this calculator?
A: Children need age- and sex-specific BMI percentiles rather than the adult categories.

Q4: What are the limitations of BMI?
A: Doesn't distinguish between fat and muscle mass, doesn't account for fat distribution, and may vary by ethnicity.

Q5: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy, though optimal may vary by individual.