Introducing… MB50 Monte Carlo Retirement Calculator
- By : Menard
- Category : Financial Planning, Investing

Scared that you might not be able to retire? Fear not! This not-so-simple calculator performs 1,000 simulations to give you valuable insight into the longevity of your savings. Of course, it’s written by no other than yours truly. So, I know exactly how it works!
This is very timely because many aspiring retirees are spooked by recent market chaos initiated by tariff-obsessed POTUS, Donald J. Trump, who seems to be determined to rob our retirement savings away from us, lol.
Without further ado.
Monte Carlo vs Historical Simulation
You see, there’s this phenomenon known as sequence-of-returns risk where the order and timing of poor investment returns can have a big impact on how long your retirement savings last.
For example, two people might have the same savings, withdrawal rate, and average return. However, if one retired just a year earlier—during an event like the 1973 OPEC oil embargo or the 2008 Great Recession—that unlucky retiree could end up being the only one who runs out of money.
Sure, you need to back-test against historical returns. But why stress-test your retirement plan solely on that? Unlike historical simulations, Monte Carlo investment returns are randomly generated based on a range of probabilities, such as historical average returns and volatility. My calculator does the same for inflation rates.
By generating a thousand randomized sequences of returns, we can capture a wider spectrum of potential sequences including the best and worst-case scenarios. After all, “past performance is not indicative of future results.”
Of course, I have to start with some assumptions:
- Your Portfolio is rebalanced to maintain the set asset allocation annually
- Social Security adjustment or COLA rises with inflation
- The Mean inflation rate is 2.5%
How to use the tool
By simply modifying the predefined parameters, you’ll get instant results. For instance, if you love your ‘stress-free’ job and plan to retire at age 67—just in time to claim your full Social Security benefits—you expect these benefits to provide you with a monthly income of $2,500, which would cover more than half of your $4,000 living expenses.
Assuming you have additional income or investments providing $500 per month, even if you anticipate living until age 87, it becomes clear that you don’t need a million dollars to retire—far from it! The probability of you retiring successfully under the above circumstances is over 80 percent!
On the other hand, if longevity runs in your family, you avoid drinking and smoking, and you stick to eating organic fruits and vegetables, you might live until age 107—and risk running out of money.
If you’re looking for an excuse not to eat your veggies, this is one of them, lol.
As you embark on your journey to secure a comfortable retirement, remember that a well-informed plan is the cornerstone of success. Hope you find this tool useful in navigating the uncertainties to make informed decisions tailored to your unique circumstances.
Whether you’re planning for a stress-free retirement or aiming to fully spend your savings in style, empowering yourself with knowledge and embracing flexibility are your best allies. Try this calculator today, and take the first step toward a brighter, more secure future. I’d love to hear your feedback!
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