Body Mass Index Calculator
Calculate Body Mass Index and health category
Free Online BMI Calculator
Body Mass Index (BMI) is a simple screening measure that uses your height and weight to estimate whether you fall into an underweight, normal weight, overweight, or obese range, based on World Health Organization (WHO) guidelines. This calculator supports both metric (cm/kg) and imperial (ft/lbs) units, and gives you your BMI instantly as you type — with everything calculated locally in your browser, so your data is never sent to a server.
How to Calculate Your BMI
- Choose your preferred unit system: Metric (cm/kg) or Imperial (ft/lbs).
- Enter your height and weight.
- Your BMI value and health category appear instantly.
- Compare your result against the standard BMI range chart shown alongside your summary.
Understanding Your BMI Result
BMI is a widely used general screening tool, not a diagnostic measurement. It does not directly account for muscle mass, bone density, or body fat distribution, so athletes or very muscular individuals may show a higher BMI despite having low body fat. Use your BMI result as a general reference point, and speak with a doctor or healthcare provider for personalized advice about your weight or health.
Frequently Asked Questions
Find answers to common questions about this tool, data privacy, and usage.
BMI is calculated by dividing your weight in kilograms by the square of your height in meters (kg/m²). This calculator does the math for you in both metric (cm/kg) and imperial (ft/lbs) units.
