Home
Back
BMI Formula:
| From: | To: |
Body Mass Index (BMI) is a simple calculation using a person's height and weight. The formula is BMI = kg/m² where kg is a person's weight in kilograms and m² is their height in meters squared. For imperial measurements, we use the formula: (weight in pounds / (height in inches)²) × 703.
The calculator uses the BMI formula:
Where:
Explanation: BMI provides a simple numeric measure of a person's thickness or thinness, allowing health professionals to discuss weight problems objectively with their patients.
Details: BMI is a screening tool that may indicate whether a person is underweight, normal weight, overweight, or obese. However, it doesn't directly measure body fat and doesn't account for muscle mass, bone density, overall body composition, and racial and sex differences.
Tips: Enter weight in pounds and height in inches. All values must be valid (weight > 0, height > 0). For most accurate results, measure height without shoes and weight with minimal clothing.
Q1: What is a healthy BMI range?
A: For adults 20 and older: Underweight (<18.5), Normal weight (18.5-24.9), Overweight (25-29.9), Obesity (≥30).
Q2: Is BMI different for men and women?
A: The calculation is the same, but the interpretation may differ slightly as women typically have more body fat than men at the same BMI.
Q3: Why is BMI not always accurate?
A: BMI doesn't distinguish between fat and muscle. Athletes with high muscle mass may have high BMI without excess fat.
Q4: Are there better alternatives to BMI?
A: More precise measures include skinfold thickness measurements, bioelectrical impedance, DEXA scans, and underwater weighing.
Q5: Should BMI be used alone to assess health?
A: No, BMI should be considered along with other assessments like waist circumference, diet, physical activity, and family history.