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's widely used in the UK healthcare system to screen for weight categories that may lead to health problems.

2. How Does the Calculator Work?

The calculator uses the UK BMI formula:

Where:

• \( weight \) — Weight in pounds (lbs)
• \( height \) — Height in centimeters (cm)
• \( 0.393701 \) — Conversion factor from cm to inches
• \( 703 \) — Conversion factor for the UK formula

Explanation: The formula first converts height from cm to inches, then calculates BMI using the standard UK formula with pounds and inches.

3. Importance of BMI Calculation

Details: BMI provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems more objectively with their patients.

4. Using the Calculator

Tips: Enter weight in pounds (lbs) and height in centimeters (cm). All values must be valid (weight > 0, height > 0). For accurate results, measure height without shoes and weight with minimal clothing.

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), and Obese (≥30).

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

Q3: Why use this UK formula?
A: This version is commonly used in the UK healthcare system and uses pounds and centimeters for convenience.

Q4: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy. However, optimal BMI may vary by age and ethnicity.

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