if your beating the game there are two telltale signs
1 you make more than 10bbs per 100 hands (think this figure is correct)
2 you have enough of a bankroll to move up to the next level (either sng or ring game)
some people will say that you need a good bb per 100 hands before you move up. I would say that if you have the bankroll to play higher then try it and if you keep winning then keep moving up as your roll allows.