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 standard BMI formula adapted for stone and inches:

Where:

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

3. Importance of BMI Calculation

Details: BMI is a simple screening tool for weight categories that may lead to health problems. While it doesn't measure body fat directly, research has shown it correlates with more direct measures of body fat.

4. Using the Calculator

Tips: Enter weight in stones, height in inches. Age is optional but provides context as BMI interpretation may vary slightly with age.

5. Frequently Asked Questions (FAQ)

Q1: Why use stone and inches?
A: This calculator is designed for those who prefer traditional British units of measurement.

Q2: What are normal BMI values?
A: Normal BMI is between 18.5 and 24.9. Below 18.5 is underweight, 25-29.9 is overweight, and 30+ is obese.

Q3: Does BMI work for everyone?
A: BMI may overestimate body fat in athletes and underestimate it in older people who have lost muscle mass.

Q4: How does age affect BMI?
A: While the same BMI categories apply to all adults, older adults may have slightly higher optimal BMI ranges.

Q5: Should children use this calculator?
A: No, children and teens need age- and sex-specific BMI percentiles rather than adult categories.