1. What is BMI?

Body Mass Index (BMI) is a simple calculation using a person's height and weight to assess body fatness. It provides a reliable indicator of body fat for most people and is used to screen for weight categories that may lead to health problems.

2. How Does the Calculator Work?

The calculator uses the standard BMI formula:

Where:

• \( weight \) — Body weight in kilograms
• \( height \) — Height in meters

Explanation: The formula divides weight by the square of height to account for the relationship between height and body surface area.

3. Importance of BMI Calculation

Details: BMI is a quick screening tool for weight categories that may lead to health problems. It helps identify potential weight problems for adults but is not a diagnostic tool.

4. Using the Calculator

Tips: Enter weight in kilograms and height in meters. For pounds and inches, convert first (1 kg = 2.2 lbs, 1 m = 39.37 inches). All values must be valid (weight > 0, height > 0).

5. Frequently Asked Questions (FAQ)

Q1: What are the BMI categories?
A: Underweight (<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 people with lost muscle mass.

Q3: Why use metric units?
A: The standard formula uses kg/m². For imperial units: BMI = (weight in lbs × 703) / (height in inches²).

Q4: Should children use this calculator?
A: No, children and teens need age- and sex-specific percentiles rather than adult categories.

Q5: What's a healthy BMI for women in Canada?
A: Same as general categories, though individual factors like muscle mass and body composition should be considered.