Decision planning under uncertainty

Retirement Simulator

Monte Carlo & historical simulation for retirement portfolios

Current result

Enter valid assumptions to calculate your plan

Results update automatically as inputs change.

Up to date

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Parameters

Simulation Mode

Starting Net Worth ($)Track your net worth with Empower

Retirement Age

Years to Fund

Withdrawal Strategy

Withdraws a fixed % of the current portfolio each year. Spending falls after losses; taxes, added costs, or a spending floor can still exhaust the portfolio.

Withdrawal Rate (%)

Lower = safer but more savings needed

Fixed Amount ($)

Min Annual Net ($)

Max Annual Net ($)

After-tax spending bounds (money in your pocket)

Crash Spending Rule

Enable

If Portfolio Drops (%)

Cut Spending (%)

Cut applies when portfolio is more than 20% below its all-time high. Spending resumes when recovered above that threshold.

Social Security

Other income streams

Annual amounts are after tax. Income pays expenses first; unused income is invested.

Healthcare Costs

Spending Smile

Taxes & Fees

Tax Rate (%)

Effective rate on withdrawals

20% off H&R Block tax filing

Investment Fees (%)

Annual expense ratio

Fix the inputs above to run the simulation.

Monte Carlo Retirement Simulator

Will your savings last through retirement? FIREwiz tests complete historical periods or 500 Monte Carlo samples drawn from annual market data from 1928–2023 to answer that question. Enter your portfolio balance, annual spending, and asset allocation to see your probability of success across a wide range of market conditions—including the Great Depression, stagflation, and the 2008 financial crisis.

Choose from 8 withdrawal strategies to find the right balance between spending flexibility and portfolio safety. Compare the classic 4% Rule against dynamic approaches like Guyton-Klinger guardrails, Variable Percentage Withdrawal (VPW), and Vanguard Dynamic Spending. Each strategy shows success rates, spending percentile ranges, and risk metrics including max drawdown and underwater years.

All results are displayed in real (inflation-adjusted) dollars, so “$40,000 in Year 20” means $40,000 of today's purchasing power. Adjust constraints like minimum spending floors and maximum ceilings, add Social Security income, or enable a glide path that shifts your allocation as you age.