Adult BMI Chart
For adults age 20 and older, CDC uses the same standard BMI categories regardless of age, sex, or race. Obesity is further divided into three classes.
| BMI category | BMI range |
|---|---|
| Underweight | Below 18.5 |
| Healthy Weight | 18.5 to less than 25 |
| Overweight | 25 to less than 30 |
| Obesity, Class 1 | 30 to less than 35 |
| Obesity, Class 2 | 35 to less than 40 |
| Obesity, Class 3 (Severe Obesity) | 40 or greater |
How Is BMI Calculated?
BMI compares weight with height. The standard adult formulas are:
U.S. customary: BMI = weight (lb) ÷ height² (in) × 703
The calculator uses the same BMI formula for adult men and women. It does not change the adult category thresholds based on sex.
What Your BMI Can and Cannot Tell You
BMI is useful as a quick screening measure, but it does not directly measure body fat and does not distinguish fat, muscle, and bone mass. It also does not show where body fat is carried. A health professional can consider BMI alongside medical history, physical examination, laboratory findings and other measures.
The displayed weight range is simply the range that corresponds mathematically to BMI 18.5 through 24.9 at the height entered. It is not a personalized target weight or medical recommendation.
BMI Calculator FAQ
Is BMI different for men and women?
For adults age 20 and older, CDC's standard BMI categories are used regardless of sex. BMI can still have individual limitations because it does not directly measure body composition.
Does BMI measure body fat?
No. BMI is based on weight relative to height. It does not directly measure body fat or distinguish fat mass from muscle and bone mass.
Can I use this calculator for a child or teenager?
No. For ages 2 through 19, CDC interprets BMI using age- and sex-specific percentiles. This CalcHarborHub calculator is intentionally limited to adults age 20 and older.
What is a healthy BMI for adults?
CDC defines the Healthy Weight category for adults as BMI 18.5 to less than 25. BMI is only one health indicator and should be considered with other factors.
Why might BMI be misleading for muscular people?
BMI uses total body weight and height, so it cannot tell whether weight comes from muscle, fat, bone, or other tissue. Someone with greater muscle mass may therefore have a higher BMI without BMI explaining their body composition.
Health information based on CDC Adult BMI Categories, CDC BMI FAQ, and CDC About BMI. This calculator is informational and is not a substitute for professional medical advice.