BMI 18, 20, 22, 25, 27, 30, 35 and 40 explained
See which adult BMI category common values fall into and learn why decimals and personal context matter.
For most adults, common BMI values map to these reference categories:
| BMI | Adult interpretation |
|---|---|
| 18 | Underweight |
| 20 | Healthy weight |
| 22 | Healthy weight |
| 25 | Overweight |
| 27 | Overweight |
| 30 | Obesity, class 1 |
| 35 | Obesity, class 2 |
| 40 | Obesity, class 3 |
Exact decimals matter at a cutoff. A displayed BMI of 25 might come from an unrounded value of 24.96 or 25.04, so retain at least one decimal before assigning a category.
The category does not describe body composition or diagnose disease. A muscular person may have a high BMI with relatively low body fat, while someone with low muscle mass may have a value in the healthy range but other risk factors. Waist measurement, blood pressure, laboratory results, fitness and medical history add context.
Use the BMI calculator for an unrounded calculation. The adult table is not appropriate for children, teenagers or the interpretation of weight gained during pregnancy.