Plan Your Retirement
With Confidence

Run thousands of market scenarios against your real tax situation. Optimize Social Security timing, Roth conversions, and withdrawal order — all in one place.

This free retirement calculator runs Monte Carlo simulations — or backtests against 97 years of actual U.S. market history — to answer the question every pre-retiree asks: how much do I need to retire? Enter your accounts, income, and spending — the optimizer finds the best combination of Social Security claiming age, Roth conversion strategy, and withdrawal order for your specific tax situation.

Portfolio trajectory (5,000 simulations)
95th median 5th Today Age 95
5,000
simulations per run
51
tax jurisdictions
10
account types
2,106
strategy combos tested
Retirement Planner demo showing Monte Carlo portfolio projections, success rate improvement from 56% to 66%, and before/after optimization comparison

What Sets This Apart

Modeling depth that generic retirement calculators skip entirely.

Year-by-Year Tax Fidelity

Progressive federal + state brackets, IRMAA surcharges, AMT, NIIT, capital gains stacking, and ACA subsidy interactions — computed every simulated year, not estimated once.

Healthcare Cost Lifecycle

ACA marketplace subsidies pre-65, Medicare Part B/D premiums, IRMAA surcharges with 2-year MAGI lookback, and long-term care event modeling.

Survivorship Modeling

Actuarial mortality tables, surviving spouse transition from MFJ to Single filing, spousal Social Security benefits, and estate computation at death.

Regime-Switching Markets

Hamilton-Markov model alternates between bull and bear regimes with distinct return/volatility profiles — not just a single average return assumption.

Withdrawal Cascade + Guardrails

Multi-account withdrawal ordering across 10 account types with Guyton-Klinger guardrails that adjust spending based on portfolio performance.

Bank-Grade Encryption

AES-256-GCM encryption at rest, derived from your password. No ads, no tracking, no data sharing. Your financial plan stays completely private.

Four Tools, One Answer

Each workflow builds on the last — from projection to optimization to stress test.

1. Baseline Simulation

Run your current plan through 5,000 market scenarios. See success probability, spending floor, and a portfolio fan chart showing the full range of outcomes.

2. Strategy Optimizer

Grid search across 2,106 combinations of Social Security claiming ages, Roth conversion brackets, IRMAA caps, and withdrawal orders to find your best strategy.

3. Sensitivity Analysis

Sweep one variable — spending, return, inflation, or retirement age — and see how your success rate responds across the range.

4. Scenario Comparison

Side-by-side "what if" analysis. Change state of retirement, spending level, or claiming age and compare outcomes instantly.

How It Works

1

Enter Your Assumptions

Income, accounts, spending, state of retirement. A guided form walks you through it.

2

Run Simulations

The optimizer tests thousands of strategy combinations across Social Security ages, brackets, and withdrawal orders.

3

Review Results

Interactive charts, downloadable spreadsheets, and a summary report with your optimal strategy.

Bank-Grade Encryption
No Ads, No Tracking
Your Data Stays Yours
Free to Use

Free Monte Carlo Simulations & Historical Backtesting Retirement Calculator

Most retirement calculators use a single average return and give you one number. Real markets don't work that way. This retirement planner runs up to 5,000 Monte Carlo simulations with regime-switching returns — modeling bull markets, bear markets, and everything in between. Or switch to historical backtesting mode and replay every retirement cohort since 1928 using actual S&P 500 returns and CPI inflation. Either way, you see the full range of outcomes, not just the average. It answers the question how much do I need to retire with a probability, not a guess.

Roth Conversion Optimizer & Withdrawal Strategy

When should you start Social Security? How much should you convert to Roth each year? Should you draw from brokerage or pre-tax accounts first? The optimizer tests thousands of strategy combinations and finds the one that minimizes your lifetime tax bill while maximizing portfolio survival. It accounts for progressive federal and state brackets, IRMAA surcharges, capital gains stacking, and the interaction between Roth conversions and ACA subsidies.

When Can I Retire?

Use the sensitivity analysis to see how your success rate changes with different retirement ages, spending levels, or market assumptions. Compare scenarios side by side — retire at 60 vs. 62 vs. 65, move to a no-income-tax state, delay Social Security to 70 — and see exactly how each choice affects your money's longevity. All data is encrypted at rest and never shared, sold, or tracked.