I recently found a retirement discussion board (the demographic is mostly early-retired, financially independent. They always direct people to this retirement calculator:
The discussions are interesting and informative ... Safe Withdrawal Rates, investing strategies, costs of ER life, inflation, and anything else financial. I am way out of their league (these are 55+ w/ mil+ portfolios living off dividends,) but I am slowly learning some pertinent stuff.
I believe in the 90s, that was a great time for mutual funds and huge compound interest earnings... I am reading The Wealthy Barber, which was written in the 90s ... and the people on those discussion boards seemed to fair well from that time, but investing is different now. Mutual funds dont earn as much as they used too... The author has released a new book (The Wealthy Barber, Returns) that will discuss current investing strategies (for retirement), so looking fwd to reading that book.
For myself, right now I am saving saving saving. Hoping I have a decent portfolio to subsidize SS! By retirement, perhaps I am living off of dividends and interest and SS subsidizes that. But I have a lot of work to do!
I do have an idea of how much I need for retirement (month to month), but that doesn't include inflation or lack of SS.