Waist measurement refers to the distance around the narrowest part of the torso, typically located above the belly button and below the rib cage. It is an important metric used in various fields, including health, fashion, and fitness, to assess body composition and determine clothing sizes. To measure the waist accurately, one should use a flexible measuring tape. The tape should be placed snugly around the waist without compressing the skin. The measurement is taken at the end of a normal exhalation, ensuring a consistent and reliable reading for tracking changes over time.