1. What is BMI?

BMI (Body Mass Index) is a simple index of weight-for-height that is commonly used to classify underweight, normal weight, overweight and obesity in adults. It's calculated by dividing weight in kilograms by the square of height in meters.

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 relates weight to height squared, providing a standardized measure that can be compared across individuals of different heights.

3. Importance of BMI Calculation

Details: BMI provides a simple numeric measure that helps identify potential weight problems in adults. While not a direct measure of body fat, it correlates well with more direct measures of body fat.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For height in centimeters, divide by 100 (e.g., 175 cm = 1.75 m). All values must be valid (weight > 0, height > 0).

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 muscular individuals and underestimate it in older people who have lost muscle mass.

Q3: Can BMI be used for children?
A: Children's BMI is calculated the same way but interpreted differently using age- and sex-specific percentiles.

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

Q5: Should athletes use BMI?
A: Highly muscular athletes may have high BMI without excess fat. Additional measures like body fat percentage may be more appropriate.