What Is a Good BMI for My Age? Charts for Adults & Seniors
The healthy BMI range of 18.5-24.9 applies to all adults, but age changes how BMI relates to health risk. Here's what the research says for adults in their 20s through 70s.
Standard BMI Ranges
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5-24.9 | Normal weight |
| 25.0-29.9 | Overweight |
| 30.0+ | Obese |
Does Age Change What's Healthy?
The WHO uses the same BMI ranges for all adults. However, as people age they lose muscle and gain fat — meaning two people at the same BMI can have very different body compositions.
BMI by Age Group
| Age Group | Standard Range | Notes |
|---|---|---|
| 20-35 | 18.5-24.9 | Standard ranges apply well |
| 36-50 | 18.5-24.9 | Standard ranges apply |
| 51-65 | 18.5-24.9 (some say up to 27) | Slightly higher may be protective |
| 65+ | 22-27 often cited | Underweight risk increases with age |
Why Seniors May Be Healthier at Higher BMI
Several large studies found adults over 65 with BMI 25-27 had better survival rates than those at lower 'normal' BMI. This is sometimes called the obesity paradox.
This does NOT mean obesity is healthy — BMI above 30 remains associated with significantly higher risk at all ages.
Beyond BMI
- Waist circumference is a stronger predictor of cardiovascular risk than BMI for most adults.
- Muscle mass matters — BMI of 27 in an active person is very different from a sedentary person at the same number.
Calculate your BMI instantly.
BMI Calculator →