If you're single and not making 100K, you're not middle class. That factors to, 60k(?) in net take home. That's only 5K a month. That's almost unlivable, and literally living paycheck to paycheck. Anything less than 100K annually (gross) is "working class" or "working poor."
I have nothing against the MANY people who are working class/poor, but let's not delude ourselves.
Same at the other end. If you count your worth in terms of XYZ dollars per year, you're, at best, "working rich." You have to have a net worth of 1M or more in assets to begin to call yourself 'rich', and I'd argue that 1M isn't what it was a couple decades ago. The new 1M is actually 2M or 3M.
30K-60K, working poor.
60K-100, working class.
100-250, middle class.
250-700, working rich.
700K+ annually, "rich" (at least after a few years at it)