1. What is BMI?

Body Mass Index (BMI) 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 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 standard BMI formula:

Where:

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

Interpretation: The result is compared against standard BMI categories:

• Underweight: BMI < 18.5
• Normal weight: BMI 18.5-24.9
• Overweight: BMI 25-29.9
• Obese: BMI ≥ 30

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 more objectively with their patients. It's used to screen for weight categories that may lead to health problems.

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: Is BMI accurate for everyone?
A: BMI may not be accurate for athletes (who may have high muscle mass), pregnant women, the elderly, or children. Other measurements like waist circumference may provide additional information.

Q2: What are the BMI categories for Asian populations?
A: Some countries use lower BMI thresholds for Asian populations (e.g., overweight ≥23, obese ≥27.5) due to different body composition.

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 lose or gain weight.

Q4: Can BMI be used for children?
A: Children's BMI is calculated differently, using percentiles based on age and sex rather than fixed thresholds.

Q5: What's a healthy BMI range?
A: For most adults, a BMI between 18.5 and 24.9 is considered healthy, though individual circumstances may vary.