BMI Calculator
Find your Body Mass Index and CDC weight category
Frequently Asked Questions
BMI = 703 × weight (lbs) ÷ height (inches)². For metric units, BMI = weight (kg) ÷ height (meters)². It's a simple ratio of weight to height squared, without accounting for body composition.
Under 18.5 is underweight, 18.5-24.9 is healthy weight, 25-29.9 is overweight, and 30 or above is obese (further split into Class I: 30-34.9, Class II: 35-39.9, Class III: 40+).
No. BMI doesn't distinguish muscle from fat, so athletes and very muscular people are often misclassified as overweight or obese despite low body fat. It also doesn't account for age, sex, or where fat is distributed on the body. It's a screening tool, not a diagnosis.
Body fat percentage, waist circumference, and waist-to-hip ratio give a more complete picture of body composition and health risk than BMI alone. Talk to a healthcare provider for a full assessment.
BMI categories (CDC)
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy weight |
| 25.0 – 29.9 | Overweight |
| 30.0 – 34.9 | Obese (Class I) |
| 35.0 – 39.9 | Obese (Class II) |
| 40.0+ | Obese (Class III) |