Does your retirement plan
actually hold up?
Monte Carlo on 156yr Shiller data, then a tax-aware year-by-year projection of every retirement year. No login.
Free calculators
Withdrawal Planner →
Tax-aware 4-way solver: surplus, needed withdrawal rate, needed portfolio, needed income. Sequential Roth/trad/taxable ordering. SS torpedo + IRMAA.
Roth Conversion Calculator →
2025+2026 IRS brackets. IRMAA tier-1 warning. SS provisional income. Bracket-filling math with full show-math breakdown.
Savings Rate Calculator →
How much of your income are you saving? See your savings rate and how it maps to years-to-retirement benchmarks.
Run a simulation
1,000 Monte Carlo simulations — conservative, base, and optimistic scenarios.
Example values pre-filled — edit to match your situation.
Why 1,000 simulations — not one guess
Most retirement calculators draw a single straight line into the future. That line is almost always wrong. Here’s why Monte Carlo gives you a more honest answer.
The future isn’t a straight line
A single projection assumes the same return every year — say, 7% forever. Real markets don’t work that way. Some years are up 30%, some are down 40%, and the order of those years matters enormously for how long your money lasts.
Bad years early hit the hardest
A rough stretch in the first few years of retirement — like 2000–2002 or 2008–2009 — forces you to sell shares while they’re down. That permanently reduces the portfolio that needs to fund the next 30 years. A straight-line average misses this completely.
1,000 different futures
Monte Carlo runs your plan through 1,000 randomized market sequences. Some paths are lucky. Some are unlucky. Most land somewhere in between. That spread is what tells you the true range of outcomes — not just the rosy middle.
A probability, not a promise
“74% success” means your portfolio lasted to your planning age in 740 of those 1,000 simulated futures. It’s an honest answer about uncertainty — not a prediction, not a guarantee, and not a sales pitch.
Can I retire with $X at age Y?
Browse pre-computed Monte Carlo simulations for common retirement scenarios. Each one is a real simulation, not a guess.
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25 simulations/month free — no credit card required. Paid plans from $9/month.
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