>>1063139That number accounts for inflation, assuming that your assets are in stocks.
For real estate income (the other popular investment choice), there are different heuristics, though. In this case, though, both housing prices and rental rates generally raise with inflation, so you're covered in that case too.
But, the main lesson here is "Know Thy Numbers". You need to have a good idea of what your regular expenses are (or will be when you go full hermit/NEET/FIRE, whatever you what to call it) before anything else. But of course, overestimating to be on the safe side is always a good thing to do if you can.
I'll be doing something similar by the end of the year, so AMA I guess.