Body mass index is used to estimate the amount of body fat a person has based on height and weight. In most cases, the higher your BMI, the more body fat you have. Diabetes and heart disease are two of the many health problems linked to having a high BMI.

BMI is an estimate and not a direct measure of how much body fat you have. The weight used to figure out BMI includes both muscle and fat, so some people may have a high BMI but not a high percentage of body fat.

As stated by the Centers for Disease Control and Prevention (CDC), people with the same BMI may have different amounts of body fat. For example, at the same BMI:

  • Women tend to have more body fat than men.
  • Older people tend to have more body fat than younger adults.
  • Athletes tend to have less body fat than non-athletes.

To figure out your BMI, enter your height and weight in the fields below. Your doctor uses your results, combined with other measures and risk factors, to find your chance of having weight-related health problems.

Please note these values apply only to adults age 20 and older. The CDC explains more about BMI for children and teenagers .




BMI Weight Status
Below 18.5 Underweight
18.5-24.9 Normal
25.0-29.9 Overweight
30.0 and Above Obese

Waist Measurement, or Circumference

Your waist measurement, or circumference, can be another good predictor of health risk. It estimates the amount of abdominal fat, or "belly fat," you have.

Where you carry your body fat can be just as important as how much body fat you have. People who carry too much fat mainly in their waist area are more likely to develop health problems than those who carry it in their hips and thighs, even if their BMI falls within the normal range.

  • For men, a healthy waist measurement should not be more than 40 inches.
  • For women, a healthy waist measurement should not be more than 35 inches.

If your waist circumference is above recommended measurements, you increase your risk for hypertension (high blood pressure), cardiovascular disease, Type 2 diabetes and other conditions.

To measure your waist circumference, place a measuring tape snugly around your waist area just above your hip bone. Do not squeeze the skin. Do not hold your stomach in. Take the measurement at the end of a normal breath.


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