Calculate your Body Mass Index in metric or imperial units and see where it falls on the standard scale.
Body Mass Index divides your weight by the square of your height: kg ÷ m² in metric, or (lbs ÷ in²) × 703 in imperial units. The calculator handles both — choose your unit system, enter weight and height, and it returns your BMI along with the standard World Health Organization category.
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obese |
Someone who is 5′9″ and 160 lbs has a BMI of about 23.6 — inside the normal range, which for that height spans roughly 125 to 168 lbs. In metric, a person 175 cm tall weighing 72 kg gets essentially the same result (23.5).
BMI is a fast, free population-level screening number — useful for spotting broad trends and flagging when a closer look is worthwhile. But it has well-known blind spots:
For a fuller picture, pair BMI with the body fat calculator, which estimates composition from circumference measurements — and treat any single number as a conversation starter with a health professional, not a diagnosis.
Often not. BMI cannot distinguish muscle from fat, so strength athletes and heavily muscled people frequently register as overweight or even obese while being extremely lean. A body-fat estimate or professional assessment is more meaningful in that case.
Not with these adult cut-offs. Children and teens are assessed with age- and sex-specific BMI percentile charts, because healthy body composition changes throughout growth. This calculator is designed for adults.
Treat it as a prompt rather than a verdict. Combine it with waist measurement, how you feel, and your medical history, and discuss it with a doctor — especially before starting any significant diet or exercise change.