Armpit to armpit is 20".  fits a size 14 well.  Nylon, rayon, spandex.  Travels well.   if this was labeled a standard tango dress brand name it would cost over $150.  But it's same styling just alfani brand at a lower price.  Snatch it up!  I'm 5'9" and it falls mid calf. 

Classic style looks good on everyone!