BMI
Estimate body mass index, healthy weight ranges, and BMI categories. Free online calculator with formulas and step-by-step solutions.
Key formula
BMI = weight / height^2
About this tool
BMI is a simple screening tool that compares weight and height to give a broad body-size classification. It is easy to calculate, which is why it is common, but users should still understand that it does not directly measure body composition.
How to use this calculator
- Enter realistic personal values and double-check the chosen unit system before calculating.
- Use the result as a planning estimate, not as a diagnosis or guaranteed outcome.
- Compare the output with your goal, context, and any relevant professional guidance.
- Review the steps to understand how the estimate was produced from your inputs.