For BL:
https://www.cnbc.com/2017/03/13/heres-how-much-you-have-to-earn-to-be-considered-middle-class.html
Here's the breakdown of how much you have to earn each year to qualify as middle-income, depending on the size of your family:
Household of one: $24,042 to $72,126
Household of two: $34,000 to $102,001
Household of three: $41,641 to $124,925
Household of four: $48,083 to $144,251
Household of five: $53,759 to $161,277