BMI Calculator

How to use this calculator

Choose a unit system, then enter weight and height as positive numbers.
Review the live result and use Copy result when you need to share it.

How the calculation works

BMI divides weight in kilograms by height in metres squared. Imperial measurements are converted before applying the same formula. The category is a general adult screening label, not a diagnosis.

Formula

BMI = weight (kg) ÷ height (m)²

Step-by-step calculation

Choose a unit system, then enter weight and height as positive numbers.
BMI divides weight in kilograms by height in metres squared. Imperial measurements are converted before applying the same formula. The category is a general adult screening label, not a diagnosis.
Check the displayed result, then copy it if needed.

Worked example

A person weighing 70 kg at 175 cm has a BMI of about 22.86, within the healthy-weight screening range.

Risk guidance

Frequently asked questions

Is BMI a medical diagnosis?

No. BMI is a general adult screening measure and does not directly measure body composition or individual health.

Does this tool send my inputs anywhere?

No. The interactive calculation runs in your browser and this site does not submit tool inputs to a backend.

How should I use the result?

Check that the entered units and values match your situation, especially around dates, breaks, and rounding.