Decision planning under uncertainty

FIREwiz

Free FIRE Calculator & Monte Carlo Retirement Simulator

Current result

Enter valid assumptions to calculate your plan

Results update automatically as inputs change.

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Adjust assumptions

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.

How FIREwiz Works

FIREwiz is a free retirement calculator that uses Monte Carlo and historical simulations to stress-test your financial plan. Enter your portfolio size, spending needs, and asset allocation to see how your money holds up across complete historical periods or 500 Monte Carlo samples drawn from annual market data (1928–2023).

Choose from 8 withdrawal strategies—including the 4% Rule, Guyton-Klinger guardrails, Variable Percentage Withdrawal (VPW), and Vanguard Dynamic Spending—and compare success rates, risk metrics, and spending paths side by side. The dashboard reports ending values and spending summaries in real (inflation-adjusted) dollars so you can plan in today's purchasing power.

Beyond retirement drawdown, FIREwiz includes an accumulation calculator to estimate your time to Financial Independence and a rent vs. buy comparison that models home ownership costs against renting and investing the difference.