I'm in my mid-40s. I have a portfolio of $1.5M and plan to withdraw $50K each year. This is a 3.3% SWR, which has never failed (100% success across all scenarios).
I know at this SWR, the portfolio is most likely to grow to be multiples of starting balance. I don't want it to grow unnecessarily large, and wish to donate everything over $2M if it ever grows to that level in that year (i.e. if portfolio grows from $1.8M to $2.3M in a given year, I will donate $300K to bring it down to $2M. If the year after it grows from $2M to $2.5M, then I will donate $500K). I don't want to wait until I'm old to give away the cash, but instead to give it away sooner.
is there a calculator that accounts for this? I want to know how much capping the upside decreases overall success rate to.