Skip to content Check your Body Mass Index in US or metric units, see your healthy weight range and save your result as a PDF.
Enter your details and press Calculate to see your BMI.
BMI is your weight in kilograms divided by your height in metres squared. Adults are grouped by fixed BMI ranges, while children and teens are compared with others of the same age and sex using CDC growth-chart percentiles.
World Health Organization classification, for men and women.
| Classification | BMI (kg/m²) |
|---|---|
| Severe Thinness | < 16 |
| Moderate Thinness | 16 – 17 |
| Mild Thinness | 17 – 18.5 |
| Normal | 18.5 – 25 |
| Overweight | 25 – 30 |
| Obese Class I | 30 – 35 |
| Obese Class II | 35 – 40 |
| Obese Class III | > 40 |
CDC BMI-for-age percentiles, by sex.
| Category | Percentile range |
|---|---|
| Underweight | < 5th |
| Healthy weight | 5th – < 85th |
| Overweight | 85th – < 95th |
| Obesity | ≥ 95th |
Your BMI divided by 25, the upper limit of the normal range. Under 1 is below that limit.
| Classification | BMI Prime |
|---|---|
| Severe Thinness | < 0.64 |
| Moderate Thinness | 0.64 – 0.68 |
| Mild Thinness | 0.68 – 0.74 |
| Normal | 0.74 – 1 |
| Overweight | 1 – 1.2 |
| Obese Class I | 1.2 – 1.4 |
| Obese Class II | 1.4 – 1.6 |
| Obese Class III | > 1.6 |
Ponderal Index is weight divided by height cubed (kg/m³). It changes less with height than BMI, so it can suit very tall or very short people. BMI is a screening measure, not a diagnosis: it does not account for muscle mass, body shape or other health factors. Speak with one of our doctors before starting any weight-loss treatment.
