Still, even within the middle class itself, there are different tiers of income — namely, upper vs. The couple welcomed a baby girl in May, meaning their income will have to stretch even further: They will likely spend roughly two-thirds of their take-home pay on child care and rent on their two-bedroom apartment. Your size-adjusted household income and the cost of living in your area are the factors we use to determine your income tier. What sets middle-class Americans apart, the study found, is that they are struggling under several burdens — low income growth, rising costs, declining job security — while those in many other countries face just one or two. Mortgage on a three- bedroom house. American households spend significantly more of their budgets on housing and less on items like food than they did in previous decades. More broadly, they are concerned about the state of the country, and how other Americans are faring.