I'm a bit confused on the SWR input and how it correlates to "Time to FI". Wouldn't inputting higher withdrawal rate in retirement years mean one would have a longer time to FI? If I put in 4% it says 7 years, if I put in 3% it says 11 years. I'm missing something obvious most likely (weirdly I don't spend a lot of time figuring out a time to FI so the Mad Fientist site is very interesting).
A higher withdrawal rate means you're okay withdrawing a larger percent of your stache, so for the same expense level, a higher WR means a lower stache needed.
For example, if you need 25k annually to live, and you want a 4% SWR then you need 625,000 (625k x 0.04 = 25k). If you want 25k at 3% SWR, then you need 833,333.33 (because 833k x .03 = 25k).
Thus a lower SWR = a higher stache needed.
A lower SWR means you are withdrawing less of your portfolio, so to be able to do that, but still have the amount you need, you'll have to have a larger portfolio (a larger portfolio, withdrawing a smaller amount), and it takes longer to get to that larger portfolio.