Adult BMI Calculator
Calculate an adult BMI estimate from metric or U.S. customary height and weight.
Data handling
- Processing
- The selected input is processed in your browser. Got A Tool does not send it to our servers.
- Retention
- Inputs and results are not saved to persistent storage. Resetting or closing this page clears the tool's working state.
- Export
- The tool may prepare a result after you run it. It downloads or copies it only when you choose that action.
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How it works
Adult BMI Calculator: a practical guide
Body mass index (BMI) is a screening calculation based on weight relative to height. This adult calculator accepts metric or U.S. customary measurements and reports the numeric BMI with common adult categories. It is intentionally limited to adults aged 20 and older.
- STEP 01
Choose metric or U.S. customary units.
- STEP 02
Enter height and weight as measured.
- STEP 03
Review the calculated BMI and the adult range labels.
What this tool does and its limits
Metric BMI is weight in kilograms divided by height in meters squared. U.S. customary measurements are converted using exact pound-to-kilogram and inch-to-centimeter factors before the calculation. The displayed value is rounded to two decimal places; adult categories use the full-precision result and the ranges under 18.5, 18.5 to below 25, 25 to below 30, and 30 or higher. The CDC describes BMI as a screening measure: it does not distinguish fat, muscle, and bone, and it is interpreted differently for children and teens. This tool is not a diagnosis or medical advice.
Inputs, selected files, and results stay in your browser. The tool does not upload them to Got A Tool or save them to persistent storage.
Questions
Adult BMI Calculator details
Is this BMI calculator for children?
No. Children and teens need age- and sex-specific BMI-for-age percentiles. Use a pediatric tool based on the relevant growth charts.
Does BMI measure body fat directly?
No. BMI uses height and weight and does not distinguish fat mass from muscle or bone.
Are the adult category boundaries included?
Yes. The page shows the category bands used: below 18.5, 18.5 to below 25, 25 to below 30, and 30 or higher.
Is this a medical diagnosis?
No. BMI is a screening measure. Discuss health questions with a qualified healthcare professional.
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