1. What is BMI?

Body Mass Index (BMI) is a measure of body fat based on height and weight that applies to adult men and women. It provides a simple numeric measure of a person's thickness or thinness.

2. How Does the Calculator Work?

The calculator uses the BMI formula:

Where:

• \( weight \) — Weight in stones (1 stone = 14 pounds)
• \( feet \) — Height in feet
• \( inches \) — Additional height in inches
• 703 — Conversion factor (kg/m² to lb/in²)

Explanation: The equation converts stone to pounds and feet/inches to total inches before calculating the standard BMI ratio.

3. Importance of BMI Calculation

Details: BMI is a simple screening tool for weight categories that may lead to health problems. It's used to identify underweight, normal weight, overweight, and obesity in adults.

4. Using the Calculator

Tips: Enter weight in stones, height in feet and inches. All values must be valid (weight > 0, height > 0). The calculator will provide your BMI and weight category.

5. Frequently Asked Questions (FAQ)

Q1: What are the BMI categories?
A: Underweight (BMI < 18.5), Normal weight (18.5-24.9), Overweight (25-29.9), Obese (≥30).

Q2: Is BMI accurate for everyone?
A: BMI may overestimate body fat in athletes and underestimate it in older people with lost muscle mass.

Q3: Why use stone and feet/inches?
A: This calculator uses traditional British units. Other versions may use metric units (kg and cm).

Q4: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy.

Q5: Should children use this calculator?
A: No, BMI interpretation for children requires age- and sex-specific percentiles.