Think of in a general sense, not some isolated situation. NAV is the key, not income. If a person or couple has $X million, you'd consider them to be rich.
I'll give this a go based on conversations with my parents when I was a little guy in the 90s. A bit of a hybrid quantitative/qualitative answer.
"Mom, how much money does it take to be rich?""I'd say THREE MILLION."(Keep in mind this was the Midwest in the 90s.)
My Mom's material reasons as told to a 10 year old?
You can pay off your house, keep a mortgage on a second home in a warmer state, pay for your children's college upfront and without loans, pay upfront for the fees to adopt a child (or two) from Romania, and host a Christmas Toy Drive for the "less fortunate" kids at your school. You can see where my Mom's kind priorities were, but I can just hear Al Bundy or Roseanne hearing all this, and without missing the chance for a joke, responding:
"Yes. Three million and maybe I can get courtside seats at the Chicago Bulls games and attract a trophy wife."Fast forward thirty years later and I would raise this threshold to at least FIVE MILLION regardless of where in the U.S. you live and what your age is.
What I also find worth determining is the term
"Generational Wealth." Chock this up as an unpopular opinion, but I find the term to be such a False Promise that it's worth questioning from a distance because of what the term ignores.
There's almost no amount of wealth that can survive a span of sixty years through a third generation. Even if invested properly (such as with the Rockefeller and Vanderbilt dynasties) uber-wealth faces an insidious and determined erosion due to inflation, division through successive inheriting, more aggressive taxing, and inevitable mishandling by undisciplined offspring.
I would say most Generational Wealth extends its usefulness only to the grandchildren (as overseen by their parents), but does not last substantially enough to be passed as an inheritance upon their parent's death, especially with how readily people live into their 80s.