Class is more about lifestyle than the money.
Yes, money plays a part but its not the whole picture.
For instance, you have three brehs who work corporate 9-5 jobs.
Breh 1 gets off of work, goes home and plays video games.
Breh 2 gets off of work, goes to Equinox and plays in a basketball league.
Breh 3 gets off of work, and goes to play a round of golf.
All the brehs are technically middle class.
But based off of their lifystyles, Breh 1 is lower middle class, Breh 2 is middle middle class, and Breh 3 is upper middle class.