BMI Calculator
Understanding Your BMI
Body Mass Index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, overweight, and obesity in adults. It is defined as a person's weight in kilograms divided by the square of his height in meters (kg/m²).
BMI Categories:
- Underweight: BMI less than 18.5
- Normal weight: BMI between 18.5 and 24.9
- Overweight: BMI between 25 and 29.9
- Obesity: BMI of 30 or greater
While BMI is a useful screening tool, it does not diagnose the body fatness or health of an individual. For example, athletes may have high BMI due to muscle mass rather than fat.
Frequently Asked Questions
Is this calculator accurate?
Yes, it uses the standard World Health Organization (WHO) formula for BMI.
Does it work for children?
This calculator is intended for adults (18+). Children need age-specific growth charts.
Why does muscle mass matter?
Muscle is denser than fat. A muscular person might have a high BMI but low body fat.
Is BMI the best health indicator?
No. It is a general screen. Waist circumference and other factors are also important.
Is this tool free?
Yes, completely free.
What units should I use?
Please use Kilograms for weight and Centimeters for height.
Do you save my health data?
Never. The calculation happens entirely in your browser.
How often should I check BMI?
Checking once a month is sufficient for most people.
What if I am "Overweight"?
Consult a healthcare provider for a professional assessment.
Can I use feet and inches?
Currently, this tool requires Metric units (cm/kg). Please convert first.