Like real estate this is nowhere near as easy as you try to make it out to be. You could divide middle class into alot more than 3 levels. It also depends upon age, upward mobility and job type. This is a rough example but you should get the picture.

For example, consider 4 househols

1.) HH lead by construction worker in their mid 50’s with 150k income (at or past peak earning)

2.) Public sector HH in their mid 40’s (2 teachers, 20 yr fire/police vet etc.) with an $150K income (close to peak earning and little upward mobility)

3.) Professional HH (engineer and nurse) in mid 30’s with 150K income (mid career with some upward mobility)

4.) Professional HH (attorney or physician) in late 20’s with a $150K income (just getting started and huge upward mobility)

I would not consider them all to be same class. Would you?