Monte Carlo Retirement Calculator
Will your money last? This free retirement calculator runs 1,000 market simulations — with Social Security, pensions, taxes, and required minimum distributions — to show your real odds of never running out.
Open the free Retirement Calculator →Free, no account, no email — your numbers stay in your browser.
What the retirement simulator shows
- Enter your age, retirement age, accounts by tax type (401(k), IRA, Roth, brokerage, cash, savings), Social Security, any pension or other income, and your planned spending.
- It runs a 1,000-scenario Monte Carlo simulation across good and bad market histories and reports your probability of success — the share of scenarios where your money lasts.
- You also get a range-of-outcomes chart, a year-by-year cash-flow and federal-tax breakdown, a full balance sheet with net worth, and personalized moves (work a bit longer, delay Social Security, Roth conversions, or a safe spending level).
Why Monte Carlo beats a single "average return"
A single average-return projection hides the real risk: the order of good and bad years matters enormously near retirement. A Monte Carlo simulation tests your plan against a thousand possible market paths, so you see the odds — not one optimistic straight line. It also models the details that make or break real plans: the taxability of Social Security, required minimum distributions after age 73, and the tax hit of each withdrawal.
Frequently asked questions
What is a Monte Carlo retirement simulation?
It runs your plan through many random market histories (here, 1,000) instead of one average return, then reports the percentage of scenarios in which your money lasts — your probability of success.
Does it include Social Security, taxes, and RMDs?
Yes. It models Social Security (including spousal and survivor rules and taxability), pensions, other income, federal taxes by bracket and filing status, and required minimum distributions from age 73 (or 75).
Is this retirement calculator free and private?
Completely free, with no account. All inputs and results stay on your device — nothing is uploaded.
How many simulations does it run?
1,000 market scenarios per plan, plus extra runs to test the recommendations. Results are reproducible for the same inputs.