1. What is Body Mass Index (BMI)?

BMI is a value derived from the mass (weight) and height of a person. It provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems more objectively with their patients.

2. How Does the BMI Calculator Work?

The calculator uses the standard BMI formula:

Where:

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

Explanation: The BMI calculation divides an adult's weight in kilograms by their height in meters squared. The result places the individual in one of several weight categories.

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, height in meters, select gender and age. All values must be valid (weight > 0, height > 0, age between 1-120).

5. Frequently Asked Questions (FAQ)

Q1: What are the standard BMI categories?
A: Underweight (BMI < 18.5), Normal weight (18.5-24.9), Overweight (25-29.9), and Obese (≥30).

Q2: Does BMI differ for men and women?
A: The BMI calculation is the same for both genders, but the interpretation may vary slightly as women tend to have more body fat than men at the same BMI.

Q3: How does age affect BMI?
A: BMI tends to increase with age until about 60-70 years, after which it tends to decrease. Older adults may need different BMI thresholds.

Q4: What are limitations of BMI?
A: BMI doesn't distinguish between muscle and fat, so athletes may be classified as overweight. It also doesn't account for fat distribution.

Q5: Is BMI accurate for children?
A: For children and teens, BMI is age- and sex-specific and is referred to as BMI-for-age. This calculator is for adults only.