User blog comment:First comes rock/Hunter x Hunter power levels/@comment-24189934-20131209003200

if you've seen Yu Yu Hakusho, they state that the gap between A class and S class (or low S class to high S class, i dont remember which) is the same as the gap between D-A class

HxH probably has the same idea

i dont agree with your list, but Ging should be in S class. Remember how it was mentioned that Ging was one of the 5 best nen users in the world? so for plot intensive purposes Ging should be S class