BMI Calculator
Calculate body mass index from height and weight. BMI is a screening measure, not a diagnosis.
What this calculator does
This tool calculates BMI from entered height and weight. BMI cannot determine health by itself. It does not capture all differences in growth or body composition. Children and teenagers need age- and sex-specific growth-chart interpretation by a qualified healthcare professional; adult cut-offs should not be applied.
How to use it
- Choose units
- enter height
- enter weight
- treat the result as general information only.
Formula and calculation method
Worked example
Important information
BMI cannot diagnose a condition. For children and teenagers, consult a qualified healthcare professional for age- and sex-specific interpretation.
Frequently asked questions
How accurate is this calculator?
It provides an estimate based on the values and assumptions entered. Verify important decisions with the relevant provider or a qualified professional.
Does this replace professional advice?
No. It is an informational tool and does not replace tax, legal, accounting, lending, investment or medical advice.
Understanding BMI and its limitations
Body mass index is calculated from weight in kilograms divided by height in metres squared. It is a screening measure at population level, not a direct measurement of body fat or an individual health diagnosis. It does not account for every factor that can affect health.
Use the result responsibly
Interpretation can differ for children and teenagers, pregnancy, athletes, older adults and some medical conditions. For anyone under 18, adult BMI categories should not be used; age- and sex-specific growth charts and a qualified healthcare professional are needed. Do not use this estimate as a target for restrictive eating or excessive exercise.
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Browse all calculators AboutResults are estimates based on entered values and assumptions. They are not professional advice. Verify important decisions with the relevant provider or a qualified professional.