A 30-inch waist size is small. Any size between 29 and 31 is considered small, with 32 to 34 being medium and 36 to 38 being large. Anything from 40 to 42 is XL, and anything above 44 is XXL.
The distance around a waist, known as waist circumference, is a common measurement. It is used to check for fat around the stomach. In order to measure this, a tape measure is placed around the body, beginning around the hipbone. Women who have more than 35 inches around the stomach and men who have more than 40 inches have an increased risk for heart disease.