What's the '4% rule'?

Spend 4% of your starting savings in year one, then raise that dollar amount with inflation each year. Historically that survived most 30-year U.S. retirements — but your safe rate depends on your horizon, your portfolio, and luck with early returns.

Why does the order of returns matter?

Once you're withdrawing, a market drop early in retirement forces you to sell at low prices, leaving less to recover. The same drop late in retirement barely matters. That's sequence-of-returns risk.

Retirement Withdrawal Lab

The big retirement question is simple: will my money last? Enter your savings, how long you need it to last, and how much you want to spend — then we run thousands of possible futures to estimate your chance of never running out. Compare spending strategies, find your safe withdrawal rate, and see why the order of returns early in retirement matters more than the average. Everything is shown in today's dollars.

Educational use only — not investment advice

This tool is for educational and informational purposes only and does not provide financial, investment, tax, legal, or accounting advice. Results are hypothetical and based on historical data and assumptions that may be inaccurate. Past performance does not guarantee future results. Consult a licensed professional before making investment decisions.

SimulationIntermediate

What is the Retirement Withdrawal Lab?

Estimate the chance your nest egg lasts through retirement, compare spending strategies, find your safe withdrawal rate, and see sequence-of-returns risk in action.

This lab answers the question every retiree loses sleep over: will my money last? It simulates thousands of possible futures for your savings as you spend them down — all in today's dollars. Compare three withdrawal strategies (a fixed inflation-adjusted amount — the famous 4% rule; a fixed percentage of the current balance; and flexible guardrails that adjust spending up and down), discover the safe withdrawal rate for your situation, and watch how sequence-of-returns risk — bad markets early in retirement — can quietly sink an otherwise healthy plan.

How to use it

1Enter your starting savings and how many years your retirement should last.
2Choose a withdrawal strategy and rate (e.g. the 4% rule), a historical portfolio or your own return/volatility, and an inflation assumption.
3Run it to see the probability your money lasts, your income each year in today's dollars, and how an early market crash (sequence risk) would change the outcome.

What you'll get

✓Probability your money lasts
✓Your safe withdrawal rate (optional finder)
✓Income each year in today's dollars (typical and tough cases)
✓Balance over time (percentile cone)
✓A sequence-of-returns-risk breakdown

New here? See it in action

Can $1M support a 30-year retirement? — Run a 60/40 portfolio with the 4% rule over 30 years to see your odds, your income, and how an early crash would change everything.

Load this example

↓ Or build your own below

Withdrawal strategy

Spend a set amount that rises with inflation each year. Stable income, but it can run dry in bad markets.

Starting savings (USD)

Years in retirement

Withdrawal rate (% of start)

Inflation (annual %)

Assumptions from

Simulations

PortfolioTotal: 100.0%

History start

History end

Method

Also find my safe withdrawal rate

How the Retirement Withdrawal Lab works

Returns are simulated and converted to real (inflation-adjusted) terms, so spending stays constant in purchasing power. Each path spends down the balance using the chosen strategy; we report the share of paths that never run out, real income statistics, and — to expose sequence risk — the average early-retirement return of paths that failed vs. survived. The safe rate is found by binary search for the target success probability.