BMI Calculator Body Mass Index
Calculate your Body Mass Index from your height and weight. Choose metric or imperial measurements and get your BMI result instantly.
View your BMI value, standard adult BMI category, estimated healthy weight range, formula and calculation steps in one simple online calculator.
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BMI Calculator
Enter your measurements
Your BMI Result
Enter your weight and height, then calculate your BMI.
What Is Body Mass Index?
Body Mass Index, commonly called BMI, is a screening measure calculated from a person's weight and height. It is commonly used to place adults into broad weight categories.
Enter Weight
Enter your current body weight using kilograms or pounds.
Enter Height
Enter your height in centimeters or inches depending on the selected unit system.
Get Your BMI
The calculator displays your BMI value and corresponding adult BMI category.
BMI Categories Explained
For adults, BMI values are commonly grouped into standard categories. These ranges are screening categories and should be interpreted in context.
| BMI Range | Adult Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy Weight |
| 25.0 – 29.9 | Overweight |
| 30.0 or higher | Obesity |
Important: These categories are intended for general adult screening. BMI does not directly measure body fat and may not accurately represent health status for every person.
How BMI Is Calculated
BMI is calculated by dividing body weight in kilograms by height in meters squared.
For imperial measurements, pounds and inches are converted within the calculation to produce the same BMI scale.
Standard Formula
Metric vs Imperial BMI
Metric
Use kilograms for weight and centimeters for height. The calculator converts height to meters when applying the BMI formula.
Imperial
Use pounds for weight and inches for height. The calculator handles the necessary conversion automatically.
Understanding the Limitations of BMI
BMI Is a Screening Measure
BMI provides a simple numerical screening measure based on height and weight. It does not directly measure body fat or provide a complete assessment of health.
Body Composition Matters
People with the same BMI can have different amounts of muscle, fat, bone and other body composition characteristics.
Adults and Children Differ
Adult BMI categories should not automatically be applied to children and teenagers. Their BMI is generally interpreted using age- and sex-specific growth references.
Use Results in Context
If you have questions about your weight, health or BMI result, consider discussing your individual circumstances with a qualified healthcare professional.
How to Use the BMI Calculator
Select Your Unit System
Choose Metric for kilograms and centimeters, or Imperial for pounds and inches.
Enter Your Weight
Enter your current weight using the selected measurement system.
Enter Your Height
Enter your height and click Calculate BMI. Your result will appear immediately.
Everything You Need to Calculate BMI
Metric Support
Calculate using kilograms and centimeters.
Imperial Support
Calculate using pounds and inches.
Detailed Results
See your BMI, category and calculation details.
Copy & Download
Keep a simple copy of your BMI result.
BMI Calculator FAQ
What does BMI stand for? +
BMI stands for Body Mass Index. It is a numerical screening measure calculated from weight and height.
How is BMI calculated? +
BMI is calculated by dividing weight in kilograms by height in meters squared: BMI = weight ÷ height².
Is BMI the same for adults and children? +
No. Adult BMI categories should not simply be applied to children and teenagers. BMI for younger people is generally interpreted using age- and sex-specific references.
Can BMI directly measure body fat? +
No. BMI is based on height and weight and does not directly measure body fat or body composition.
Is this BMI calculator free? +
Yes. The BMI calculator is free to use and does not require registration.
Health Information Disclaimer
This calculator is provided for general informational and educational purposes. BMI is a screening measure and should not be used as a diagnosis or as a substitute for professional medical advice. Individual health circumstances can vary.
Calculate Your BMI Now
Enter your height and weight above to calculate your Body Mass Index quickly and view your calculation details.
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