How Long Will My Retirement Savings Last?

The most widely cited rule in retirement planning is the 4% rule: withdraw 4% of your portfolio in your first year of retirement, then adjust that dollar amount for inflation every year after. Historically, a diversified portfolio (roughly 60% stocks, 40% bonds) using a 4% withdrawal rate has survived at least 30 years in the vast majority of historical market scenarios in the U.S., including periods that started right before major crashes.

A 4% withdrawal rate implies a portfolio of 25 times your annual expenses — this is where the popular "25x rule" comes from. If you spend $60,000 a year, a $1.5 million portfolio at a 4% withdrawal rate is designed to last three decades or more.

The 4% rule is a useful anchor, but it was derived from a specific historical dataset and a specific asset allocation. Your actual runway depends on several variables that a static rule can't capture:

• Your withdrawal rate. Drop to 3.5% and your money can plausibly last indefinitely; push past 5% and you meaningfully increase the risk of running out before you die.
• Your investment returns before and after retirement. A more aggressive allocation can extend your runway but adds volatility right when you can least afford a bad sequence of returns.
• Sequence-of-returns risk. A market downturn in your first few retirement years does far more damage than the same downturn a decade in, because you're selling assets at depressed prices to fund withdrawals.
• Inflation. If your withdrawals grow with inflation but your portfolio doesn't keep pace, your runway shortens even though the dollar amount you're withdrawing looks unchanged.
• Major one-off expenses — a new roof, a wedding, a medical event — that don't show up in a flat annual withdrawal assumption.

Rather than relying on a rule of thumb, you can run a year-by-year simulation: start with your current portfolio, apply your expected pre- and post-retirement investment returns, subtract your inflation-adjusted annual withdrawal each year, and see exactly which year (if any) your balance hits zero.

Our retirement calculator does exactly this. Enter your current savings, expected monthly expenses, pre- and post-retirement return assumptions, and inflation rate, and it plots your full wealth trajectory — including the exact age your money is projected to run out, if it does at all.

Consider someone retiring at 60 with a $1.2 million portfolio, spending $55,000 a year (a ~4.6% initial withdrawal rate), expecting 5% average returns post-retirement and 3% inflation. That's a higher withdrawal rate than the classic 4% rule, so their runway is meaningfully shorter than 30 years — likely closer to 22-25 years, putting them at risk in their mid-to-late 80s depending on how markets actually perform. Reducing spending to $48,000 (a 4% rate) or delaying retirement by a few years to grow the portfolio further would materially extend that runway.

Your retirement savings will last as long as your withdrawal rate, returns, and inflation allow — and small changes in any of those three levers compound into very different outcomes over 20-30 years. Model your specific numbers rather than assuming a generic rule applies to you.