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 calculated by dividing weight in kilograms by height in meters squared.

2. How Does the Calculator Work?

The calculator uses the standard NIH BMI equation:

Where:

• \( weight \) — 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 screening tool for weight categories that may lead to health problems. It is used to screen for weight categories that may lead to health problems but it is not diagnostic of the body fatness or health of an individual.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. 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: Are there limitations to BMI?
A: Yes, BMI doesn't account for muscle mass, bone density, overall body composition, and racial/sex differences.

Q3: Is BMI accurate for athletes?
A: BMI may overestimate body fat in athletes and others with muscular builds, and underestimate body fat in older persons who have lost muscle mass.

Q4: Should children use this calculator?
A: No, children and teens need age- and sex-specific percentiles rather than the adult BMI categories.

Q5: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy, though optimal BMI may vary by population.