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's calculated by dividing a person's weight in kilograms by the square of their height in meters.

2. How is BMI Calculated?

The BMI formula is:

Where:

• \( weight \) — Weight in kilograms (kg)
• \( height \) — Height in meters (m)

Example: For 11 stone (69.8532 kg) and height 1.75 m: 69.8532 / (1.75 × 1.75) = 22.8 kg/m²

3. BMI Categories

Standard BMI Categories:

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

4. Using the Calculator

Tips: Enter weight in kilograms (11 stone = 69.8532 kg) and height in meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is 11 stone in kg?
A: 11 stone equals exactly 69.8532 kg (1 stone = 6.35029 kg).

Q2: Is BMI accurate for everyone?
A: BMI has limitations as it doesn't distinguish between muscle and fat. Athletes may have high BMI without excess fat.

Q3: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy, but individual factors should be considered.

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

Q5: How often should I check my BMI?
A: Periodic checks can track changes, but focus on overall health rather than BMI alone.