BMI Calculator
Work out your Body Mass Index from height and weight — metric or imperial — and see the WHO adult category.
Your measurements
Adult WHO categories. This is a screening figure, not a diagnosis.
Body Mass Index
—
Enter height and weight
- Healthy range (this height)
- —
- Underweight: BMI under 18.5
- Normal: 18.5 – 24.9
- Overweight: 25 – 29.9
- Obese: 30 or above
Frequently asked questions
How is BMI calculated? +
BMI = weight (kg) ÷ height (m)². In imperial units we convert pounds and inches to metric first. The result is rounded to one decimal place.
What do the WHO categories mean? +
For adults: under 18.5 is underweight, 18.5–24.9 is the normal range, 25–29.9 is overweight, and 30 or above is obese. Categories differ for children — this tool is for adults.
Is BMI a medical diagnosis? +
No. BMI is a screening number. Muscle mass, age and other factors matter. Speak to a clinician about your health.
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