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Will Your Money Last Your Lifetime?

Know Your Odds. Improve Them.

Stop guessing about your financial future. Get your real success rate — then find out exactly what moves it.

Who uses SuccessRate
Pre-Retirees (5–10 yrs out)
Confirm your date is realistic. See the impact of 1–2 more working years on your success rate.
New Retirees
Validate spending sustainability and understand sequence-of-returns exposure.
Mid-Retirement
Reassess after market moves. Plan Roth conversions before RMDs hit.
Legacy Planners
Balance spending with estate goals. Stress-test against worst-case markets.

Most Calculators Cut Corners. This One Doesn't.

Honesty over false precision — including the bad outcomes most tools hide from you.

Fat Tails

Crashes Happen More Than the Bell Curve Predicts

Standard models underestimate tail risk. SuccessRate uses a Student-t distribution (df=5), so rare catastrophic market events occur with realistic frequency — not wishful statistics.

Regime Switching

A Major Crash Early Retirement Is Far More Damaging Than at Year 20

Two separate market regimes — normal and stress — with Markov transitions model the real clustering of downturns. Sequence-of-returns risk is modeled, not glossed over.

Tax Precision

The Gap Between Gross and Spendable Wealth Can Exceed 15%

Progressive federal and state brackets, IRMAA Medicare surcharges, RMDs, and capital gains stacking — calculated year by year. Not estimated. Not averaged. Calculated.

Not a Spreadsheet. Not a Guess.

Professional-grade modeling that runs right in your browser.

Strategy Comparison

Side-by-side simulations with shared random seeds — every decision has a measurable impact in percentage points.

Full Tax Engine

Progressive federal + state brackets, IRMAA, RMDs, capital gains stacking. DP-optimized Roth conversions minimize lifetime taxes.

Social Security Timing

Find the optimal claiming age for you and your spouse. See exactly how delay changes your odds of success.

Goal & Legacy Tracking

Set a spending floor and bequest target. See the probability you meet both goals across every simulated future.

Five Levers That Move Your Success Rate

Run baseline → test one change at a time → combine improvements → re-run annually.

1
Reduce Spending Rate
Single most powerful lever. Dropping from 5% to 4% improves success more than almost any investment change.
2
Diversify Globally
At high US valuations, international stocks carry higher expected returns. Test 40/20/10/30 US/Intl/EM/Bonds.
3
Dynamic Spending
Guardrails strategy typically adds 4–8 percentage points to success rate vs. rigid fixed withdrawal.
4
2-Year Cash Buffer
Draw from cash during downturns. Improves the 5th percentile floor significantly.
5
Reduce Tax Drag
Roth conversions before RMDs + optimal withdrawal ordering. Can add 5–10 percentage points to after-tax wealth.

Your Financial Data Stays With You

The app runs entirely as WebAssembly in your browser tab. No servers, no accounts, no tracking — ever.

✓ No account required ✓ No email collected ✓ No data sent anywhere ✓ Works offline after load

Know Your Odds. Improve Them.

Stop guessing about your financial future. Get your real success rate — then find out exactly what moves it.

Launch Free Demo →

Want the full version? Request early access