How to use Adult BMI Calculator

1. Prepare the required inputs

Calculate adult body mass index using metric or imperial measurements and see the screening category. Use the units and options beside each field. Results update as inputs change; reset returns to example inputs.

Measurement units: Metric (cm, kg) / Imperial (inches, pounds)
Height (cm / inches): minimum 1, maximum 300
Weight (kg / pounds): minimum 1, maximum 1400

2. Try a worked example

70 kg and 170 cm gives BMI 24.22, in the adult healthy-weight screening range.

3. Understand the calculation

BMI = weight in kilograms ÷ (height in metres)².

4. Read the assumptions

For adults only. BMI does not measure body fat or diagnose health. Pregnancy, muscle mass and other factors can make the category less useful.

5. Check and compare results

Match entered values to their labels and units. Review output labels alongside the assumptions, then change one input at a time. A currency selector changes display labels without converting amounts. Use the available save or copy actions and retain the input values so the estimate can be reproduced.

6. Fix an invalid input

Complete required fields and respect the listed bounds. Check date order, age relationships and mode-specific requirements where relevant; the error message identifies invalid combinations. Reset to example inputs to recover. A valid calculation applies to its stated model and does not verify a real-world outcome.