What Is a Normal Waist Size?

A waist size is considered normal if it is 35 inches or less for women and 40 inches or less for men, according to the National Institutes of Health (NIH). The risk for type 2 diabetes and heart disease increases with greater waist circumferences. The NIH publishes a table of the risks of obesity-associated diseases by body mass index and waist circumference that gives visitors to its website an idea of whether their waist sizes are indicative of any pending health problems.