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:

Where:

• \( weight \) — Weight in pounds (lb)
• \( feet \) — Height in feet (ft)
• \( inches \) — Additional height in inches (in)
• 703 — Conversion factor (kg/m² to lb/in²)

Explanation: The formula converts height to total inches, squares it, divides weight by this value, then applies the conversion factor to get BMI in standard units (kg/m²).

3. Importance of BMI Calculation

Details: BMI is used to screen for weight categories that may lead to health problems. It's a quick, inexpensive method that correlates with body fat for most people.

4. Using the Calculator

Tips: Enter weight in pounds, height in feet and inches. All values must be valid (weight > 0, height > 0). For metric measurements, use a different calculator.

5. Frequently Asked Questions (FAQ)

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

Q2: Is BMI accurate for everyone?
A: No. BMI may overestimate body fat in athletes and underestimate it in older adults with lost muscle mass.

Q3: Why use feet and inches instead of just inches?
A: This format matches how most people in the US report their height (e.g., 5'7" rather than 67 inches).

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

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