how long will my retirement funds last depends less on your total balance and more on the withdrawal rate, inflation, and how your money is invested.
Vanguard's 2024 "How America Saves" report found the average 401(k) balance for workers in their early 60s sits near $250,000 — a sum that could last 15 years or 40 years depending on choices you make. The problem is that most people guess instead of modeling.
This guide shows you the safe withdrawal math, the real impact of fees and inflation, and the tools that project your money over time, so you can answer the question with numbers rather than hope.
Start With the 4% Rule as Your Baseline
The 4% rule says you withdraw 4% of your portfolio in year one, then adjust that dollar amount for inflation each year. It became famous from the Trinity Study, updated by Morningstar's "State of Retirement Income" research, which now estimates a safe starting rate closer to 3.7% for a 30-year horizon with a stock-heavy portfolio.
A 4% rate on $500,000 gives you $20,000 per year before taxes.
That simple formula gives you a first estimate of how long will my retirement funds last. Divide 100 by your withdrawal rate to get a rough duration — 4% implies about 25 years. But the rule assumes a steady mix of stocks and bonds, and it ignores sequence-of-returns risk when markets fall early in retirement.
- Test at 3%, 4%, and 5% to see the range of outcomes.
- Keep at least one year of spending in cash to avoid selling stocks in a downturn.
- Recalculate your rate every three years based on actual portfolio performance.
How to apply this: take your starting balance, multiply by 0.04, and check whether that annual figure covers your essential expenses plus taxes.
Add Inflation to Get the Honest Answer
Inflation is the hidden variable that changes how long will my retirement funds last more than almost anything else. The Social Security Administration notes that benefits receive annual cost-of-living adjustments, and the Federal Reserve targets 2% inflation per year over the long run.
At 2%, prices roughly double in 36 years — so a $60,000 retirement budget today needs about $120,000 in four decades.
Most online calculators let you set an inflation assumption. Use 2.5% to 3% to stress-test your plan. A portfolio that looks safe at 0% inflation can run out several years sooner once you raise it.
Why Purchasing Power Matters More Than Returns
A 6% nominal return with 3% inflation leaves only about 3% real growth. Track your real return, not the headline number, when you project longevity.
The Cost of Being Too Conservative
Keeping everything in cash feels safe but loses ground to inflation. According to the U.S. Bureau of Labor Statistics Consumer Price Index data, even moderate inflation erodes cash balances every year.
How to apply this: reopen your projection and raise the inflation input by one full percentage point, then note how many years drop off your plan.
Run a Monte Carlo Simulation, Not a Single Guess
A single straight-line projection tells you one outcome. Monte Carlo simulations run thousands of market scenarios and show the probability your money lasts. Commonly used tools include Personal Capital (now Empower) for tracking net worth and retirement projections, and Portfolio Visualizer for backtesting withdrawal strategies against real market history.
| Approach | What it tells you | Action to take |
|---|---|---|
| 4% rule | Rough annual withdrawal | Multiply balance by 0.04 |
| Straight-line calculator | One fixed projection | Set realistic return and inflation |
| Monte Carlo simulation | Probability of success | Target 80–90% success rate |
| Bucket strategy | Cash, bonds, stocks by timeline | Split holdings into 3 buckets |
Aim for an 80–90% success probability rather than 100%, which requires saving far more than most people need.
How to apply this: run your numbers through a free Monte Carlo tool and note the success percentage at your planned withdrawal rate.
Audit Fees and Taxes Before You Commit
Fees quietly shorten how long will my retirement funds last. The U.S. Department of Labor warns that a 1% difference in fees can reduce a retirement account balance by roughly 28% over 35 years. On a $600,000 portfolio, an extra 1% fee costs about $6,000 every year.
Taxes matter just as much. Withdrawals from traditional 401(k)s and IRAs are taxed as ordinary income, while Roth accounts come out tax-free. The IRS explains that required minimum distributions begin at age 73 for most savers under the SECURE 2.0 rules, forcing withdrawals and taxable income whether you need the cash or not.
- Compare your fund expense ratios against low-cost index funds.
- Plan Roth conversions in low-income years to reduce future taxes.
- Check whether state taxes apply to retirement income where you live.
How to apply this: log into your account, list every fund's expense ratio, and replace anything above 0.50% with a low-cost alternative.
Stress-Test the Scenarios You Can't Control
A long life, a market crash, and long-term care costs are the three forces most likely to break your plan. The Society of Actuaries' mortality tables show a healthy 65-year-old couple has a meaningful chance that at least one spouse lives past 90 — so planning to age 95 is reasonable. Meanwhile, the U.S.
Department of Health and Human Services has reported that a person turning 65 today has roughly a 70% chance of needing some long-term care.
Model these scenarios one at a time to see how long will my retirement funds last under pressure:
- A 20% market drop in your first two years of retirement.
- Living to age 95 instead of 85.
- Two years of long-term care costs at $100,000 annually.
How to apply this: add a "bad year" to your projection and confirm your cash bucket can cover two years of spending without selling stocks.
Frequently Asked Questions About how long will my retirement funds last
Should I include Social Security when calculating how long will my retirement funds last?
Yes, include it as a guaranteed income floor that reduces how much your portfolio must cover. The Social Security Administration reports that benefits replace about 40% of pre-retirement earnings for average workers. If your benefit covers most essentials, your portfolio only needs to fund the gap — which can extend how long will my retirement funds last by several years.
What happens if I retire during a market crash?
Sequence-of-returns risk means early losses hurt more than later ones. A 30% drop in year one can permanently shorten your plan even if markets recover. Hold one to two years of spending in cash and delay large withdrawals during downturns to protect how long will my retirement funds last.
Can I withdraw more than 4% if I have a pension?
Possibly. A pension or annuity acts like a bond, adding stable income. Some advisors suggest a higher withdrawal rate from the investment portfolio when guaranteed income covers basic needs. Model your combined income first, since the answer to how long will my retirement funds last depends on total cash flow, not one account.
How does part-time work affect my timeline?
Even modest earned income reduces portfolio withdrawals. Earning $20,000 a year part-time can cut your withdrawal rate by a full percentage point on a $500,000 portfolio. That single change often adds several years to how long will my retirement funds last, and it also delays the start of Social Security, raising the benefit.
What if I have a chronic illness or family history of short lifespans?
A shorter life expectancy lets you spend more aggressively or buy fewer longevity protections. Consider a higher withdrawal rate, keep a larger emergency fund, and revisit your answer to how long will my retirement funds last annually with your doctor's input rather than a generic table.
Conclusion
The answer to your retirement timeline comes down to a few controllable levers:
- Your withdrawal rate sets the rough duration — 4% implies about 25 years.
- Inflation and fees shrink your money more than most people expect.
- Monte Carlo tools show probability, not false certainty.
- Cash buffers and part-time income protect against bad early markets.
Start today: multiply your balance by 0.04, run one Monte Carlo projection, and check your fund fees. Those three steps will tell you far more about how long will my retirement funds last than any rule of thumb alone — and give you a plan you can adjust every year.
