1. What is 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 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 measure body fat directly, research has shown that BMI correlates to direct measures of body fat. It is used as a screening tool to identify possible weight problems in adults.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For accurate results, measure 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 BMI categories for adults?
A: Underweight: BMI < 18.5; Normal weight: BMI 18.5-24.9; Overweight: BMI 25-29.9; Obesity: BMI ≥ 30.

Q2: Is BMI accurate for everyone?
A: BMI may not accurately reflect body fat percentage in athletes (who may have high muscle mass), the elderly (who may have lost muscle mass), or pregnant women.

Q3: 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.

Q4: Can children use this calculator?
A: No, this calculator is for adults only. Children and teens need age- and sex-specific percentiles to interpret BMI.

Q5: What's a healthy BMI range?
A: For most adults, a BMI between 18.5 and 24.9 is considered healthy and associated with the lowest health risks.