There is no definitive answer to what is 'hung'.Someone above said they're 7 and don't consider it hung.Look at a ruler.7 inches is big.People's view on size changes person to person.Some women for example think 6 is big,others say 8 is average.Everyone's needs and opinions differ to the point where it makes all talk about what is 'big' irrelevant.
Medically,the average size is supposed to be 5-5.5.So if you're above that,you should consider yourself big to a degree.I'm 7 3/4 long measuring along the top(8 if you measure underneath) and 5 1/4 around fully erect and I consider it a good size.
Most of the women I've been with have made some comment as to how 'big' it feels when we're having sex.Of course the way you use it plays a big role also.My GF tells me I hit all different spots because of the different techniques I use,despite the fact that she says she's been with a guy she'd estimate about a foot long prior to me.She says sex with him was not enjoyable because he didn't know how to use his size.He just tried to see how far he could penetrate her and make himself feel like a stud.Sorry going off topic a bit.....