1. What is Body Mass Index (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 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 standard 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. While it doesn't directly measure body fat, it correlates with direct measures of body fat and offers a reasonable indicator of body fatness for most people.

4. Using the Calculator

Tips: Enter your weight in kilograms and height in meters. For accurate results, measure your weight without heavy clothing and height without shoes. All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

Q1: What are the standard BMI categories?
A: Underweight: BMI less than 18.5; Normal weight: BMI 18.5-24.9; Overweight: BMI 25-29.9; Obesity: BMI 30 or greater.

Q2: Is BMI the same for all ethnicities?
A: While the formula is the same for all ethnicities, health risks associated with BMI may vary between different ethnic groups.

Q3: What are the limitations of BMI?
A: BMI doesn't account for muscle mass, bone density, overall body composition, and racial and sex differences. Athletes may have a high BMI but not have excess body fat.

Q4: How often should I check my BMI?
A: For most adults, checking BMI once every 6-12 months is sufficient unless you're actively trying to change your weight.

Q5: Is BMI applicable to children?
A: BMI is calculated the same way for children but interpreted differently, using age and sex-specific percentiles.