A 36" pair of pants are meant for guys with a 36" waist. Some of these pants are meant to hang around your butt. Some are meant to hug tightly to your waist.

A 36" pair of pants are meant for guys with a 36" waist. Some of these pants are meant to hang around your butt. Some are meant to hug tightly to your waist. If you measure the waists of those pants, they will differ. That does not mean the size is false.