Calculate your Body Mass Index (BMI) using metric or imperial measurements. BMI is a simple screening tool to indicate whether you are at a healthy weight for your height.
| BMI Range | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal weight |
| 25.0 – 29.9 | Overweight |
| 30.0 and above | Obese |
Metric: BMI = weight (kg) ÷ height (m)²
Imperial: BMI = (weight (lbs) ÷ height (in)²) × 703
BMI is a useful screening tool but has limitations. It does not distinguish between muscle and fat, so muscular individuals may score high without excess body fat. It also does not account for age, sex, or fat distribution.
For most adults, a BMI between 18.5 and 24.9 is considered healthy. Ranges can differ by age and ethnicity — some organizations use lower cutoffs for people of Asian descent.
This calculator is for adults 20+. For children and teens, BMI is assessed using age- and sex-specific growth charts (BMI-for-age percentiles) to account for natural changes during growth.
BMI is a starting point, not a diagnosis. Consult a healthcare professional for a complete assessment including waist circumference, blood pressure, cholesterol, and lifestyle factors.
The factor 703 converts the result from lbs/in² to the standard kg/m² unit, accounting for the conversions between pounds and kilograms and between inches and meters.