1. What is BMI?

BMI (Body Mass Index) 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 for stone and pounds:

Where:

• \( weight \) — Weight in stone and pounds (converted to total pounds)
• \( height \) — Height in inches
• 703 — Conversion factor (kg/m² to lbs/in²)

3. Importance of BMI Calculation

Details: BMI is a simple screening tool to identify potential weight problems in adults. 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 stone and pounds, height in inches. All values must be valid (weight components ≥ 0, height > 0).

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 persons who have lost muscle mass.

Q3: Why use stone and pounds?
A: This calculator uses the traditional British imperial system where weight is commonly measured in stone and pounds.

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

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