BMI Calculator
Calculate your body mass index and see the healthy weight range for your height.
What is BMI?
Body mass index (BMI) is a quick screening number that compares your weight with your height. It's used by doctors and health agencies like the CDC and WHO to flag weight ranges that may carry health risks.
BMI = weight (kg) ÷ height (m)²
BMI = 703 × weight (lb) ÷ height (in)²
For example, 170 lb at 5 ft 10 in (70 inches) gives 703 × 170 ÷ 4,900 = 24.4, in the healthy range.
BMI categories for adults
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy weight |
| 25 – 29.9 | Overweight |
| 30 and above | Obesity |
Limits of BMI
BMI doesn't measure body fat directly. Very muscular people can have a high BMI without extra fat, and older adults can have a "healthy" BMI while carrying more fat than it suggests. It also doesn't account for where fat is stored, which matters for health. Use it as a starting point, and talk to a doctor for a full picture.
This calculator is for adults 20 and over. Children and teens use BMI-for-age percentiles instead.