There are hundreds of retirement tools online. They can project forward based on some specified average rate of return, rate of inflation, specified variance of that rate of return, and any additions you fee in. There are also tools that will do all of that based on the historical rate of return for stocks or bonds in various mixtures.
But none of them even think of making an effort of planning for upheaval. They all presume, and it’s not a bad presumption, but it is only a presumption that society functions over the next XX years as it has over the past 150.
The odds for that do not look good. Too many parameters are ugly at a magnitude never before seen.
By farmland.
I used a 401 calculator. It was free from my bank. I just put in my information, and it made the picks for me. It did a pretty good job, a better job than when I did it myself.