Free online tool
BMI calculator
Work out body mass index (BMI) for adults from height and weight, in metric or US units.
Works in your browserNothing is sent anywhereNo sign-upFree
Units
Your BMI–
< 18.5 Under18.5–24.9 Healthy25–29.9 Over30+ Obesity
For adults aged 18 and over. BMI is a rough guide: it does not tell muscle from fat, and it is not right for children, pregnancy or athletes. It is not medical advice; talk to a doctor about your health.
Questions
Good to know
How is BMI worked out?
Weight in kilograms divided by height in metres squared. 68 kg and 1.70 m gives 68 ÷ (1.70 × 1.70) = 23.5.
Is my information saved?
No. The sum happens in your browser and nothing is saved or sent.
Is BMI the same for children?
No. Children and teenagers use special age charts. Ask a doctor or school nurse.
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