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 standard 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 weight status across different heights.

3. Importance of BMI Calculation

Details: BMI is a simple screening tool that can indicate whether a person is underweight, normal weight, overweight, or obese. While it doesn't measure body fat directly, research has shown that BMI correlates with more direct measures of body fat.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For most accurate results, measure weight in the morning before eating and after using the toilet. Measure height without shoes.

5. Frequently Asked Questions (FAQ)

Q1: What are the BMI categories for adults?
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 overestimate body fat in athletes and those with muscular builds, and underestimate it in older persons who have lost muscle mass.

Q3: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy. However, optimal BMI may vary by age, ethnicity, and other factors.

Q4: 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.

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