1. What is BMI?

Body Mass Index (BMI) is a simple calculation using a person's height and weight. The formula is BMI = kg/m² where kg is a person's weight in kilograms and m² is their height in meters squared. It provides a reliable indicator of body fatness for most people.

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: The formula divides weight by the square of height to account for the fact that weight increases with the square of height.

3. Importance of BMI Calculation

Details: BMI is a simple, inexpensive screening method for weight category—underweight, healthy weight, overweight, and obesity. Tracking BMI reduction over time can help monitor weight loss progress.

4. Using the Calculator

Tips: Enter current weight in kg, height in meters. Optionally include initial weight to calculate BMI reduction. 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), Obesity (≥30).

Q2: How much BMI reduction is significant?
A: Even a 5-10% reduction in BMI can lead to significant health improvements.

Q3: Are there limitations to BMI?
A: BMI doesn't distinguish between muscle and fat, so athletes may have high BMI without excess fat.

Q4: How often should I check my BMI?
A: For weight management, checking every 2-4 weeks is reasonable.

Q5: Should children use this calculator?
A: Children need age- and sex-specific BMI percentiles, not adult categories.