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 the weight in kilograms divided by the square of the height in meters.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

• \( weight \) — Body weight in kilograms (kg)
• \( height \) — Height in feet (ft)
• \( 0.3048 \) — Conversion factor from feet to meters

Explanation: The height in feet is first converted to meters by multiplying by 0.3048, then the standard BMI formula is applied.

3. BMI Categories

Details: According to WHO:

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

4. Using the Calculator

Tips: Enter weight in kilograms and height in feet. All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

Q1: Is BMI different for men and women?
A: The same BMI formula applies to both men and women, though body composition differs between genders at the same BMI.

Q2: What are the limitations of BMI?
A: BMI doesn't account for muscle mass, bone density, or fat distribution. Athletes may have high BMI without excess fat.

Q3: Why convert feet to meters in the calculation?
A: The standard BMI formula requires height in meters. We convert feet to meters (1 ft = 0.3048 m) for accurate calculation.

Q4: Is this calculator only for men?
A: While designed for men, the calculation works the same for women. The interpretation may differ slightly.

Q5: How often should I check my BMI?
A: For most adults, checking every few months is sufficient unless you're actively trying to change your weight.