"Compared with the rest of the world, a middle class American" is... wealthy. "To be among the wealthiest half of the world last year, an adult needed to own only $3,210 in net assets." To compare yourself to other Americans, "the median American family had $81,000 in net worth in 2013."
The majority (71%) of the global
population -- collectively own only 3%
of global wealth, according to Ana Swanson, writing in The Washington Post: https://www.washingtonpost.com/news/wonk/wp/2016/01/21/you-might-be-among-the-richest-people-in-the-world-and-not-realize-it/