Your entire financial future, modeled year by year.
The most comprehensive FI simulator on the web. Taxes, inflation, Social Security, Roth conversions, life events, and Monte Carlo — all in one engine.
Peak: $11.2M
Monthly savings
$1,500/mo
Retire at age
55
Annual return
7%
Real lives don't fit a single formula.
Spreadsheets work right up until the moment your life gets interesting. What happens when you buy a house in year 5, take a sabbatical in year 10, start Social Security at 62, and convert $50,000 a year from your traditional IRA to Roth from 50 through 55? Each of those decisions cascades into the others. The house changes your tax deduction, which changes the optimal Roth conversion amount, which changes the year you cross the FI threshold, which changes when Social Security claiming becomes worthwhile.
A spreadsheet asks you to resolve those interactions by hand. A simulator resolves them for you. The engine running underneath this page chains taxes, withdrawals, growth, and life events across a fifty-year horizon, then lets you change one variable and watch every downstream year recompute in milliseconds.
Seven steps, every year, for fifty years.
Each simulated year runs through the same seven-step pipeline. Assets appreciate, the portfolio compounds, money flows in (income, dividends, Social Security), the tax engine takes its cut, money flows out (spending, debt service, withdrawals), the allocation rebalances, and the year closes with new totals feeding the next iteration.
The pipeline is deterministic and pure. Same inputs always produce the same outputs — which is why a Monte Carlo run can vary just the market-return inputs across thousands of iterations and produce a clean probability distribution at the end.
Asset appreciation
Real estate, businesses, collectiblesMarket growth
Portfolio compounds at assumed returnInflows
Wages, dividends, Social SecurityTaxes
Federal brackets, capital gains, RMDsOutflows
Spending, withdrawals, debt serviceRebalance
Allocation drift correctionYear-end totals
Net worth, cash, tax basisString together different chapters of your life.
Most retirement calculators assume your life is one phase: you work, you save, you retire, you spend. Real careers branch. Work in the US for fifteen years, go nomad in a 0%-tax country for five, then return for ten — the engine resolves which scenario applies in each year and chains taxes, savings rates, and asset allocation across phases.
Free accounts get one life path; Pro unlocks unlimited so you can compare alternatives side by side. The example to the right shows a three-phase US → nomad → coast path; the same composition supports a sabbatical, a graduate-school stint, a second-career pivot, or any combination of the above.
US career
Age 25–40Nomad year
Age 40–45Return & coast
Age 45–65Change one variable. Watch thirty years update.
The hero demo above is not a video. It's the actual projection engine running in your browser. Drag the monthly-savings slider and the entire future repaints. Push the retirement age out two years and watch the depletion line flatten. This is the same interaction loop the full simulator runs — only with three levers instead of fifty.
When you create a free profile, the demo's three levers are joined by everything else: tax filing status, employer match, debt amortization schedules, Social Security claiming ages, Roth conversion windows, and arbitrary one-off life events. The interaction loop stays exactly as responsive — the math just gets honest.
One projection is a guess wearing a suit.
A deterministic projection picks one set of return assumptions and shows you one outcome. That's useful as a midpoint, but useless as a probability. Markets don't pay the average return every year; they pay clusters of good years and clusters of bad ones, and the order matters more than the average.
Monte Carlo simulation re-runs your entire plan against ten thousand randomized market histories — bootstrap-sampled from a century of real data — and reports the percentage of runs in which your portfolio survives to age 95. That number isn't a marketing flourish. It's the single most useful piece of information a retirement plan can produce, and it's what separates planning from guessing.
Monte Carlo is the headline Pro feature. The deterministic engine — taxes, Social Security, Roth conversions, RMDs — is fully available on the free tier.
What's included on each tier
| Feature | Free | Pro |
|---|---|---|
| Deterministic 50-year projection | ||
| Federal tax brackets and capital gains | ||
| Social Security claiming model | ||
| Roth Conversion Ladder | ||
| 14 standalone calculators | ||
| 1 profile, 1 life path, 3 scenarios | ||
| Unlimited profiles, life paths, and scenarios | ||
| Monte Carlo (10,000+ runs) | ||
| Plaid bank sync | ||
| AI Financial Advisor | ||
| PDF and CSV export |
Everything you might be wondering
Yes — federal income tax (current brackets), capital gains tax, RMDs, and Social Security taxation are modeled year by year. State tax is supported via configurable scenarios.
Yes. Add a "House Purchase" life event with the year, price, down payment, mortgage rate, and term. The simulator updates your cash flow, asset base, and tax deductions automatically.
A spreadsheet runs one path; the simulator chains together scenarios, life events, and tax pivots over a 50-year horizon. It also handles Monte Carlo, RMDs, and Roth conversion sequencing — each of which is impractical to model by hand.
Monte Carlo runs your plan against thousands of randomized market histories and reports the percentage of runs in which your portfolio survives. It converts a binary "yes/no" projection into a probability distribution.
For most users, yes — the deterministic engine handles taxes, Social Security, RMDs, and Roth conversions. Monte Carlo adds probabilistic context but isn't required for a baseline plan.
Pro accounts can export results to PDF and CSV. The shared scenario / community feature is on the roadmap.
10,000 runs typically complete in 5–15 seconds. The compute happens server-side; the client streams progress.
No. Bank linking via Plaid is a Pro feature for automatic data sync; the simulator works with manual data entry alone.