1. What is BMI?

Body Mass Index (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 the weight in kilograms divided by the square of the height in meters (kg/m²).

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 calculates body mass per unit of height squared, providing a standardized measure of body composition.

3. Importance of BMI Calculation

Details: 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.

4. Using the Calculator

Tips: Enter weight in kilograms, height in meters, and age in years. All values must be valid (weight > 0, height > 0, age ≥18).

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), and Obese (≥30).

Q2: Does BMI apply to everyone?
A: BMI may not be accurate for athletes (high muscle mass), pregnant women, or the elderly who may have lost height.

Q3: Why is age included if not in the formula?
A: While age doesn't affect BMI calculation, it provides context for interpreting results as healthy weight ranges change with age.

Q4: What's a healthy BMI for older adults?
A: For those over 65, a BMI of 23-29.9 may be healthier than the standard range due to age-related body composition changes.

Q5: Should BMI be the only measure of healthy weight?
A: No, waist circumference, body fat percentage, and other measures should also be considered for a complete assessment.