BMI Calculator
Calculate body mass index in metric or imperial units and see the WHO weight category.
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cm
kg
lb
Your BMI
–
- Healthy weight for your height –
- BMI prime (BMI ÷ 25) –
| WHO category | BMI |
|---|---|
| Underweight | below 18.5 |
| Healthy weight | 18.5 – 24.9 |
| Overweight | 25 – 29.9 |
| Obesity | 30 and above |
For adults aged 18 and over. BMI is a screening measure, not a diagnosis. Consult a healthcare professional.
How to use the BMI Calculator
- Choose metric or imperial units.
- Enter your height and weight.
- Read your BMI, the WHO category and the healthy weight range for your height.
About BMI
BMI = weight (kg) ÷ height (m)². The categories are the World Health Organization adult ranges: underweight below 18.5, healthy 18.5–24.9, overweight 25–29.9 and obesity 30 or above. Some health bodies use lower thresholds for people of Asian ethnicity.
BMI is a screening measure only. It does not distinguish muscle from fat and is not valid for children, pregnant women or athletes. Talk to a healthcare professional about your health.
Frequently asked questions
Can children use this calculator?
No. Children and teenagers need age- and sex-specific BMI percentiles.
Is BMI accurate for muscular people?
Not always. Muscle is dense, so athletes can have a high BMI without excess body fat.