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 pounds, ounces, and inches:

Where:

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

Explanation: The formula first converts the total weight (pounds + ounces converted to pounds) and then calculates the ratio of weight to height squared, with a conversion factor to get the standard BMI units.

3. Importance of BMI Calculation

Details: BMI is widely used as a screening tool to identify possible weight problems in adults. While it doesn't measure body fat directly, research has shown it correlates with direct measures of body fat.

4. Using the Calculator

Tips: Enter weight in pounds and ounces, height in inches. All values must be valid (weight ≥ 0, height > 0). For most accurate results, measure weight without heavy clothing and height without shoes.

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: BMI may overestimate body fat in muscular individuals and underestimate it in older people who have lost muscle mass.

Q3: Why include ounces in the calculation?
A: For precise measurements, especially important when tracking small weight changes in children or for medical purposes.

Q4: Can I use this for children?
A: While the calculation is the same, BMI interpretation for children requires age- and sex-specific percentiles.

Q5: What's a healthy BMI range?
A: For most adults, 18.5 to 24.9 is considered healthy, but individual health factors should also be considered.