I have a Med BD in floral chambray. At its narrowest, it looks like 19.5". At the waist, it is about 20".I have a Small BD in one of the newer overdyes (which ran a size bigger). At it's narrowest it is 19.5". The waist is around 20.75"They've been through the wash a few times, but not the dryer. hope that helps.
12/30/14 at 1:17pm