Safe Withdrawal Rate Calculator
See how long your portfolio lasts, find your maximum sustainable withdrawal rate, and stress-test the 4% rule against a bad first decade — the risk a single number hides.
Portfolio balance from age 65 to 95 withdrawing 4.0% initially. It lasts the full horizon.
A constant-return model can’t reproduce the historical 4% rule and hides real market volatility. Use the stress test — and treat any single number as a rough guide, not a promise.
For educational use only. This calculator provides estimates based on the assumptions you enter and does not constitute investment, tax, or legal advice. Results are not guarantees of future performance. Consult a qualified professional before making financial decisions.
How the safe withdrawal rate calculator works
Once you have saved for retirement, the question flips: not “how do I build a portfolio,” but “how much can I spend from it without running out?” This calculator applies the classic approach — take a percentage of your portfolio in year one, then increase that dollar amount with inflation every year after — and shows whether the money lasts through the horizon you set. It also does something most calculators avoid: it lets you stress-test the answer.
The headline result is simple to read: your money either lasts through your planning age or it runs out at a specific age, marked on the balance chart. But the honest story is in the bad-first-decade toggle, which shows how the same plan fares if poor returns arrive early. That single switch captures the risk that a smooth average return conceals — and it is the most important thing on this page.
The math, and why to distrust a single number
Each year, the withdrawal is the first-year amount grown by inflation: withdrawal_k = portfolio × rate × (1 + inflation)^(k−1). The balance is drawn down at the start of the year and the remainder grows: balance = (balance − withdrawal) × (1 + return). The calculator iterates this to your planning age, records the age the balance would hit zero, and — by bisection — finds the highest first-year rate that still survives the full horizon.
Here is the crucial caveat, stated plainly: the famous 4% rule did not come from a model like this. It came from testing withdrawals against real historical sequences of US returns, which lurched up and down. A constant-return projection cannot reproduce that and, worse, it hides sequence-of-returns risk entirely — the danger that a bad first decade does damage a good final decade can never undo. That is why the stress test exists: flip it on and watch an “average-safe” plan fail.
Every input, explained
Portfolio at retirement
The invested balance you begin retirement with. Everything scales from this, but the rate you draw and the returns you earn matter more to whether it lasts than the starting figure alone.
Initial withdrawal rate
Your first-year withdrawal as a percent of the portfolio. Four percent is the traditional anchor; early retirees often choose less. This is the lever with the most influence over whether — and when — you run out.
Annual return and inflation
Your assumed average return during retirement and the rate your withdrawals grow to keep pace with prices. The gap between them, the real return, is what actually sustains spending. A high headline return with high inflation is not as safe as it looks.
Retirement age and planning age
Together they set the horizon the portfolio must survive. A longer retirement lowers the safe rate, because there is more time for inflation to compound and for a bad sequence to strike. Plan to a conservative age.
Assumptions and limitations
- Constant returns. The single biggest simplification — real markets are volatile, and volatility is the whole risk.
- No taxes or fees. Withdrawals from tax-deferred accounts are taxable; fees reduce returns. Both shorten how long money lasts.
- Portfolio-only. Social Security and pensions are not modeled; they would let you withdraw less and last longer.
- Rigid withdrawals. Real retirees flex their spending; flexibility dramatically improves sustainability and is not modeled here.
How this fits the bigger picture
Withdrawal planning is the last mile of retirement. To decide whether you will even reach a portfolio this size, start with the retirement calculator. Because guaranteed income lets you draw down less, estimate yours with the Social Security estimator. And to keep building the portfolio in the first place, the 401(k) calculator shows how contributions and the employer match compound over a career.
Frequently asked questions
- What is the 4% rule?
- The 4% rule is a guideline that says you can withdraw 4% of your portfolio in your first year of retirement, then adjust that dollar amount for inflation each year, with a strong historical chance of not running out over a 30-year retirement. It came from studies of past US market returns, not from any law of finance. It is a useful starting point, not a guarantee.
- Where did the 4% rule come from?
- It traces to research by financial planner William Bengen in the 1990s and the related Trinity Study, which tested fixed withdrawal rates against historical US stock and bond returns. Both looked at rolling 30-year periods and a specific stock/bond mix. Because it is grounded in one country’s particular history, it may not hold for different horizons, allocations, or futures.
- Why can’t a simple calculator reproduce the 4% rule?
- Because the rule emerged from volatile historical sequences, while a calculator like this applies one smooth average return every year. A constant return hides the single biggest danger in retirement — the order in which good and bad years arrive. That is exactly why this tool includes a bad-first-decade stress test rather than pretending a single number is safe.
- What is sequence-of-returns risk?
- It is the risk that poor returns early in retirement do lasting damage, because you are withdrawing from a shrinking balance that then has less left to recover when markets rebound. Two retirees with the same average return can have wildly different outcomes depending on whether the bad years came first or last. Early losses are far more dangerous than late ones.
- How does the bad-first-decade toggle work?
- It lowers your assumed return by five percentage points for the first ten years of retirement, then restores it, keeping the long-run average lower but front-loading the pain. Watch how a plan that comfortably survives with steady returns can run out years early once the losses come first. It is a simple illustration of a very real risk.
- Is 4% still a safe withdrawal rate today?
- It remains a reasonable anchor, but many researchers argue for flexibility — trimming withdrawals in down years, or starting a bit lower if you retire early or expect lower returns. The right rate depends on your horizon, your allocation, and your willingness to adjust spending. Use the max-sustainable-rate output as a reference and stay flexible.
- What if I retire early and need the money to last 40+ years?
- Longer retirements demand a lower withdrawal rate, because there are more years for a bad sequence to strike and more inflation to outrun. Many early retirees plan around 3% to 3.5% rather than 4%. Extend the horizon in this calculator and watch the maximum sustainable rate fall.
- Should I include Social Security or a pension here?
- This tool models withdrawals purely from your portfolio. Guaranteed income like Social Security or a pension reduces how much you must pull from investments, which effectively lets your portfolio support a lower withdrawal rate and last longer. Estimate that income separately and subtract it from your spending needs before setting a rate.
- Does a higher stock allocation raise the safe rate?
- Historically, portfolios with a substantial stock allocation supported higher safe withdrawal rates than very conservative ones, because growth is what outpaces inflation over a long retirement. But more stocks also mean deeper drawdowns and more sequence risk. This calculator uses a single return input rather than modeling allocation directly.
- What does “maximum sustainable rate” mean here?
- It is the highest first-year withdrawal rate that, under your steady-return assumption, still lasts the full horizon without depleting. It is a clean mathematical ceiling for your inputs — not a recommendation. Because real returns are volatile, prudent plans withdraw meaningfully below this theoretical maximum.