Important Disclaimer — Not Financial Advice
The results from this calculator are for informational and educational purposes only. They are not a guarantee of actual outcomes and should not be considered financial, investment, tax, or legal advice. Always consult a qualified professional for advice tailored to your specific financial situation. See our Terms of Service and Privacy Policy for more information.
The Monte Carlo Simulation calculator uses probabilistic modeling to project thousands of potential investment outcomes based on varying market conditions. It is essential for investors who want to move beyond static linear projections to understand the true range of risk and potential success for their portfolios.
A Monte Carlo simulation is a computational technique that uses repeated random sampling to model the probability of different outcomes in an investment portfolio, accounting for market volatility and uncertainty.
Monte Carlo simulations run thousands of hypothetical market scenarios to estimate the range of possible portfolio outcomes over time.
This method helps investors assess the likelihood of achieving specific financial goals, such as retirement savings targets.
The simulation incorporates factors like asset allocation, expected returns, and volatility to generate a probability distribution of outcomes.
Results are typically presented as a range of possible ending portfolio values, highlighting best-case, worst-case, and median scenarios.
S_t = S_{t-1} * exp((mu - 0.5 * sigma^2) * dt + sigma * epsilon * sqrt(dt))
This formula uses Geometric Brownian Motion to simulate price changes, where the future value depends on the expected return, volatility, and a random variable representing market uncertainty.
An investor nearing retirement might use this tool to determine if their current savings rate and asset allocation can withstand a decade of poor market performance. By running 10,000 simulations, the user can see the probability of their portfolio lasting through their expected lifespan. This helps in adjusting withdrawal strategies, delaying retirement, or shifting to a more conservative asset mix to mitigate the risk of running out of funds. It transforms abstract market volatility into a clear statistical probability of success.
If you have a $500,000 portfolio with a 7% expected annual return and 15% volatility, the simulation might reveal you have an 85% chance of reaching $1,000,000 in 10 years. Conversely, it warns that in the worst 5% of market scenarios, your portfolio could potentially drop to $350,000.
These authoritative sources inform our calculator methodology and ensure accuracy.
Written by Qasem Mohammed
Financial tools developer and founder of QFINHUB. All calculators are built with industry-standard formulas and reviewed for accuracy. Content is for educational purposes only — always consult a qualified financial professional for decisions about your specific situation.
Last updated: June 25, 2026 ·About QFINHUB · Editorial Policy
Last reviewed by Qasem Mohammed — June 25, 2026
AI & Software Engineer, Founder & Lead Developer at QFINHUB · Editorial Policy
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Median Final Value
$37,306.93
5th Percentile
$11,923.25
Worst 5% of outcomes
95th Percentile
$101,240.98
Best 5% of outcomes
Probability of Loss
+3.30%