Estimate body mass index from height and weight, with adult classification shown only for people age 20 or older.
Calculate with the BMI Calculator
Enter the details below. Your values stay in this browser and are validated before results are shown.
BMI Calculator results
How to use the BMI Calculator
- Select the requested method and unit system where available.
- Enter measured values carefully using the labels and active units.
- Select Calculate or press Enter.
- Read the estimate together with its method, assumptions, limitations, and safety notice.
Worked example
At 70 kg and 175 cm, BMI is approximately 22.9. At 154.3 lb and 5 ft 8.9 in, the result is approximately the same.
Interpreting the estimate
BMI is a screening measure, not a diagnosis. For adults, the result can be compared with population reference categories alongside other health information.
Limitations
- Adult categories are not applied below age 20.
- Muscle mass, pregnancy, age, body composition, and some disabilities can affect interpretation.
- BMI does not directly measure body fat or individual health.
Frequently asked questions
Why is there no adult category below age 20?
Children and teenagers require BMI-for-age percentiles that vary by age and sex. This calculator does not implement those validated growth charts.
Is the BMI calculator a medical assessment?
No. It provides an educational estimate from the values entered and cannot account for every individual or clinical factor.
Does CalculatorCheck store my health information?
No. The calculation runs in your browser, and the entered values are not sent to a server or added to the page URL.