Monte Carlo Retirement Calculator
We're now ready for an improved calculator that lets you include volatility in your plans.
The "Monte Carlo" in the title doesn't mean that the odds are against you and you're going to crap out in the big casino of life; it's the generic term used for a computer model that runs many random iterations and lets you see your chance of meeting your goal.
The inputs are different than the previous calculators.
This time you specify your desired annual withdrawal amount as well as the number of years you want the account to last; together, those two numbers form your goal
The output is also different.
This time you get a probability distribution - sort of a lopsided "bell curve" - showing your chance of success and failure.
The red portion of the curve is the chance of failure - outcomes where the money will run out too early.
The number at the top of the graph is your overall chance of success.