Adult BMI Calculator
Calculate adult body mass index from height and weight with metric or imperial input units.
YOUR CALCULATION
Result
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Calculation steps
Work through one step at a time or reveal the complete calculation. The steps use your current inputs.
How to calculate
Convert weight and height to SI and compare calculated adult BMI with the stated screening bands.
BMI=weight in kg/(height in m)²
Worked example
70 kg and 1.75 m give BMI≈22.8571429. A weight of 80 kg at 2 m gives BMI 20.
Assumptions and input details
For adults aged 20–100 only; this is a screening calculation, not a diagnosis, body-fat measurement or recommended target weight. Adult interpretation has limitations in pregnancy, high muscularity and some clinical contexts. This page does not apply child/teen percentiles or infer individual health from BMI alone. Inputs remain in your browser.
References: CDC: adult BMI calculator
Unit definitions
Unit selection is independent of language. Each selector contains only units for its physical quantity. Calculations use defined base units internally.
Choose from 23 length definitions, including explicitly labelled regional measures. Area conversions square the length factor; geometric volumes cube it.
The 19 mass definitions distinguish avoirdupois and troy measures, metric and regional measures. Japanese kin is 600 g; mainland Chinese shijin is 500 g.
Regional measures are not interchangeable merely because their names look similar. This is a documented selection, not a claim to include every historical unit.
NIST measurement tables · Japanese traditional units · Mainland China and Hong Kong unit distinctions
Using this calculator
Can I enter my own problem?
Yes. Replace the example values with your own inputs. The result, calculation steps, tables and applicable diagrams update from those inputs. Blank or invalid values clear the result; example values are never silently substituted for missing inputs.
Are the results exact?
Results use floating-point arithmetic and displayed rounding. Read the formula, assumptions and any stated data precision before interpreting the result.
Is my input uploaded?
The calculation runs in your browser. No account, file upload or external AI service is required. Inputs are not saved between page reloads.
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