BMI Categories: What Is a Healthy BMI Range?
The standard adult BMI categories — underweight, healthy weight, overweight and obesity — and what a healthy range means.
Want your BMI right now?
Open the BMI Calculator →More BMI guides
Frequently asked questions
What are the BMI categories?
Underweight below 18.5, healthy weight 18.5–24.9, overweight 25–29.9, and obesity 30 or above, per WHO and CDC.
Is a BMI category a diagnosis?
No. It is a population screening band that may flag higher or lower average risk, not a verdict on an individual’s health.
Why might a fit person be classed as overweight?
Because BMI cannot distinguish muscle from fat, muscular individuals can have a high BMI while being healthy.
Do the categories apply to everyone?
They are for adults and can fit differently across ages and ethnic groups; children and teens use age- and sex-specific charts instead.
What should I do if my BMI is outside the healthy range?
Treat it as a prompt to speak with a healthcare provider, who can interpret it with other measures of health.
Is BMI the only measure that matters?
No. Waist circumference, activity, diet, blood pressure and other factors all contribute to a fuller health picture.
The standard BMI categories
Body mass index sorts adults into broad weight categories used for health screening. The World Health Organization and CDC ranges are: underweight below 18.5, healthy weight 18.5–24.9, overweight 25–29.9, and obesity 30 and above.
What the categories are for
These bands are a quick, population-level screening tool, not a diagnosis. They flag where weight may be associated with higher or lower health risk on average, which can prompt a conversation with a healthcare provider — but they say nothing definitive about any one person’s health.
Important limitations
BMI uses only height and weight, so it cannot tell muscle from fat. Very muscular people may fall into "overweight" while being fit, and the cut-offs can fit differently across ages and ethnic groups. It is a starting point, not the whole picture.
If your BMI category prompts any concern, a doctor can interpret it alongside other measures such as waist circumference, blood pressure and overall health. The categories are general information and are not medical advice.
Results are estimates for general guidance in United States and may not reflect the latest local rates, fees or rules. Check official sources before making decisions.