Share of U.S. middle class population 2015, by age

This statistic shows the percentage of the U.S. adult population that belong to the middle class from 1971 to 2015, by age. In 2015, about 50 percent of U.S. adult residents were part of the middle class.
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. Middle class income ranges from about 42,000 U.S. dollars to about 126,000 U.S. dollars per year for a three-person household.