BMI Formula:
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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. It provides a reliable indicator of body fatness for most people.
The calculator uses the standard BMI formula:
Where:
Explanation: BMI is calculated by dividing weight in kilograms by the square of height in meters.
Details: BMI is a simple, inexpensive screening tool for weight category—underweight, healthy weight, overweight, and obesity. It can help identify potential weight problems in adults.
Tips: Enter weight in kilograms and height in meters. All values must be valid (weight > 0, height > 0). For pounds and inches, convert first (1 kg = 2.2 lbs, 1 m = 39.37 inches).
Q1: What is a healthy BMI range?
A: For adults, 18.5-24.9 is considered healthy. Below 18.5 is underweight, 25-29.9 is overweight, and 30+ is obese.
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 metric units?
A: The standard BMI formula uses kg and m. For imperial units, the formula is (weight in lbs × 703) / (height in inches²).
Q4: Does BMI differ for men and women?
A: The same BMI ranges apply to both men and women, though body composition differs between genders.
Q5: What are the limitations of BMI?
A: BMI doesn't distinguish between muscle and fat, doesn't account for fat distribution, and may not be accurate for certain ethnic groups or body types.