Body & Energy
BMI Calculator
BMI in one number, its standard category, and — more useful than either — the healthy weight range calculated for your specific height, plus your BMI Prime.
Your numbers
Result
Your BMI—
Category—Standard adult bands
Healthy weight range for your height—
BMI Prime—
How it works
BMI is weight in kilograms divided by height in metres, squared. It was designed in the 1830s as a population statistic, and at population level it tracks health risk well. Its bands are fixed: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, 30 and above obese. Because height is squared, the healthy weight range widens quickly as height grows — the range shown here is computed from your height, not read from a generic chart.
BMI Prime simply divides your BMI by 25, the top of the healthy band, which makes comparisons across heights a little easier to read.
Good practice & limits
- Measure height honestly in the morning — most adults are 1–2 cm shorter by evening.
- BMI cannot see muscle. A strength athlete at 27 may be leaner than a sedentary person at 23; use the waist measurement alongside it.
- One reading is a snapshot. The direction of travel over three months says far more.