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 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 BMI formula:

Where:

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

Explanation: The formula calculates body mass per unit of surface area, providing a standardized way to compare weights across different heights.

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 objectively with their patients.

4. Using the Calculator

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

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 not accurately reflect body fat in athletes (high muscle mass), elderly (loss of muscle mass), or certain ethnic groups.

Q3: How often should I check my BMI?
A: For most adults, checking every 6-12 months is sufficient unless you're actively trying to change your weight.

Q4: Are there limitations to BMI?
A: BMI doesn't distinguish between muscle and fat, and doesn't account for fat distribution which affects health risks.

Q5: Should children use this calculator?
A: No, children and teens need age- and sex-specific BMI percentiles rather than the adult categories.