Retirement Simulator

Starting Balance

Current portfolio value

Current Age

Your age today

Asset Allocation

Allocate between stocks and bonds (must total 100%)

Asset Class	Allocation (%)
Stocks
Bonds
Total	100%

Investment Fees

Annual fee charged by your advisor or platform

Typical Advisor 1.25% per year ArcVest 0.40% per year Custom Set your own

Annual Contribution

Amount saved per year

Contribution Growth Rate

Annual increase in contributions (%)

Years of Contributions

How many years will you save?

Retirement Age

Age when withdrawals begin

Years in Retirement

Planning horizon

Withdrawal Strategy

Choose how to determine your annual retirement spending

Fixed Amount Set a specific dollar amount % of Assets Percentage of portfolio at retirement

Annual Withdrawal

Amount withdrawn per year

Withdrawal Rate (%)

4% is a common rule of thumb for sustainable withdrawals

Withdrawal Inflation

Annual increase in withdrawals (%)

Guyton-Klinger Guardrails

Enable dynamic spending guardrails

Guardrail Band (%)

Trigger threshold above/below initial rate

Adjustment (%)

Spending cut or raise when triggered

How guardrails work: Each year, if your current withdrawal rate rises above the initial rate × (1 + band), spending is cut by the adjustment %. If it falls below the initial rate × (1 − band), spending is raised. This helps preserve capital in down markets while allowing increases in good times.

Simulation Settings

Simulation Count

More scenarios = more accuracy

Rebalancing

Portfolio rebalancing strategy

Expected Returns & Risk

Set expected annual returns and volatility for each asset class

Stock Return (%/year)

Expected annual return

Stock Volatility (%)

Standard deviation (volatility)

Bond Return (%/year)

Expected annual return

Bond Volatility (%)

Standard deviation (volatility)

Correlation

Correlation between stocks and bonds

Degrees of Freedom

Fat tails: Use 5 for realistic extremes, 30+ for normal distribution

Compound Annual Growth Rate (Before Fees)

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Expected median portfolio CAGR excluding fees

Simulation Mode

Simple Single skewed-t distribution with your parameters above Regime-Switching 3-state Markov model: Calm, Crash, Inflation regimes

Simple Distribution: Returns are sampled from a Skewed Student's t-distribution with negative skew (−0.3) to model fat tails and crash risk. Correlation is applied via Cholesky decomposition. At df ≥ 30, the distribution converges to normal.

Taxes

Model the impact of taxes on retirement withdrawals

Taxable Portion (%)

Estimated taxable % of your portfolio

Estimated Tax Rate (%)

Estimate of blended tax rate for portfolio withdrawals

Historical Stress Test

Test your retirement plan against historically bad times to retire. Select a scenario below to see how your portfolio would have performed using actual market returns from that period.

October 1929

The Great Depression

Stocks fell 89% over 3 years. One of the worst times in history to retire with a stock-heavy portfolio.

January 1966

The Lost Decade(s)

Start of a 16-year secular bear market. Stocks went nowhere while inflation eroded purchasing power.

January 1973

Oil Crisis & Stagflation

Stocks dropped 48% over 2 years. Stagflation meant both stocks AND bonds suffered.

March 2000

Dot-Com Bubble Peak

Tech-heavy portfolios lost up to 80%. S&P 500 didn't recover for 13 years on a real basis.

October 2007

Global Financial Crisis

Stocks fell 57% in 17 months. Retiring at the peak before the Great Recession was brutal.

January 2022

Inflation Shock

Both stocks AND bonds fell together. A rare 60/40 portfolio disaster as Fed hiked rates.

Custom Date

Choose Your Own

Pick any month from January 1928 to December 2025.

How it works: Your portfolio grows normally until retirement using Monte Carlo simulation. At retirement, the simulation switches to actual historical returns from your selected scenario. If you outlive the historical data, Monte Carlo simulation resumes for the remaining years.

Year-by-Year Breakdown

After running the simulation, this tab will show the detailed year-by-year progression of the median scenario. The median scenario is the one that ranked 500th out of 1,000 simulations by final balance.

Run the simulation to see detailed year-by-year results

Median Failure Scenario

This tab shows the year-by-year progression of the median failure scenario. Failed scenarios are ranked by when the money runs out, and this shows the median of those failures.

Run the simulation to see failure scenario details (if any)

Simulation Results

Success Rate

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Median Final Balance

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10th Percentile

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90th Percentile

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