Median net worth of U.S. families 1983-2013, by income tier
This study defined middle class income households as those with an income between 67 and 200 percent of the U.S. median household income, after adjustment for household size. In 2014, the middle class income ranged from about 42,000 U.S. dollars to about 126,000 U.S. dollars per year for a three-person household.