Frequently asked questions
What is a healthy BMI for adults?
According to the CDC and WHO, a BMI between 18.5 and 24.9 is considered normal/healthy for most adults. However, these thresholds were developed from predominantly white European populations. Research suggests lower thresholds (23 for overweight, 27.5 for obese) may be more appropriate for Asian populations, and some studies suggest the normal range for Black Americans may be slightly higher.
Is BMI accurate for athletes and muscular people?
No — BMI uses only weight and height, so it cannot distinguish muscle from fat. A bodybuilder or NFL linebacker may have a BMI in the overweight or obese range despite having very low body fat. For athletes, measurements like body fat percentage (via DEXA scan, hydrostatic weighing, or bioelectrical impedance) are more meaningful than BMI.
What BMI is considered obese in the US?
A BMI of 30 or above is classified as obese by the CDC. Obesity is further divided into Class 1 (BMI 30–34.9), Class 2 (35–39.9), and Class 3 / severe obesity (40+). As of 2024, approximately 42% of US adults are classified as obese — up from about 30% in 1999.