BMI Calculator
Calculate your Body Mass Index in metric or imperial units and see your WHO weight category and healthy range.
100% Client-SideChoose metric or imperial, enter your height and weight, and your BMI appears instantly.
How to use the BMI Calculator
- 1
Choose Metric (kg, cm) or Imperial (lb, ft and in).
- 2
Enter your height.
- 3
Enter your weight.
- 4
Read your BMI, its WHO category and the healthy weight range for your height.
Frequently asked questions
BMI is weight in kilograms divided by height in meters squared. For example, 70 kg at 1.75 m gives 70 ÷ 1.75² = 22.9. Imperial values are converted to metric first.
The WHO adult categories are: underweight below 18.5, healthy 18.5–24.9, overweight 25–29.9, and obese 30 or above (class I 30–34.9, class II 35–39.9, class III 40+).
No. BMI doesn't distinguish muscle from fat, so athletes may score high, and it doesn't account for age, sex or ethnicity. It's a quick screening number, not a diagnosis — talk to a doctor about your health.
Not reliably. Under 20, BMI must be compared against age- and sex-specific percentile charts, which this calculator doesn't use. The categories shown are for adults.
Your BMI divided by 25, the upper limit of the healthy range. A value below 1.0 means you're under that limit; 1.2 means 20% above it.
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