Belt with buckle

Belts with buckles are measured in inches that correspond to a waist size however, most people do not wear belts on the waist, they wear them closer to the hips. Measure from the end of the pin of the buckle (where it touches the buckle) to the middle hole on the belt. Generally there are 5 holes for size adjustment, with a 1" space between each, so the middle hole will the be average size of the belt.

Belt without buckle

For at tie belt (no buckle), lay the belt out flat and measure the belt portion end to end, including half of the tie portion. This is will give you the medium size of the belt.