I'm a 12 on bottom.  I'm tall, so looks can be deceiving.
I just got a charcoal suit jacket from Express and it's also a size 12.  But I have a Tahari blazer that's a 6.  Wide range there, but I run about a 10 on top, average I'd say.  But my booty?  Yeah, it's not going anywhere anytime soon lol.
 
 5'10", HW: 326/SW: 280/CW: 181/Goal: 165
                                  5'10", HW: 326/SW: 280/CW: 181/Goal: 165