Retirement Longevity Calculator
Use this tool to estimate how long your retirement savings may last based on spending, income, expected returns, and inflation.
How this retirement calculator works
A common retirement question is simple: “Will I run out of money?” This calculator helps answer that by projecting your savings forward month by month. It starts with your current nest egg, subtracts your monthly expenses, adds any monthly income, and then applies your expected investment growth.
It is designed for fast planning, not tax filing or legal advice. Still, it gives a powerful first estimate you can use for retirement income planning, withdrawal strategy design, and stress-testing your assumptions.
Key inputs and why they matter
1) Starting retirement savings
This is your total investable portfolio at retirement (401(k), IRA, taxable accounts, cash reserves set aside for spending, etc.). The larger this number, the longer your plan can usually sustain withdrawals.
2) Monthly spending
This is your lifestyle cost in today’s dollars. Include housing, healthcare, food, travel, transportation, gifts, and buffer money. Underestimating spending is one of the most common retirement planning mistakes.
3) Other monthly income
Enter reliable income streams such as Social Security, pension payments, rental net income, or annuity income. More guaranteed income usually means less pressure on your portfolio withdrawals.
4) Expected annual return
This is your long-term average growth assumption. Be realistic. Many retirees use conservative assumptions because sequence-of-returns risk (bad returns early in retirement) can damage sustainability even when long-term averages look fine.
5) Inflation
Inflation is critical. If your spending rises with inflation while your portfolio return is weak, your purchasing power can erode quickly. Turning inflation adjustment on gives a more realistic long-range estimate.
Interpreting your result
- “Lasts X years” means your projected balance reaches zero around that time under your assumptions.
- “Lasts beyond projection period” means you still have money at the end of the selected horizon.
- The year-by-year table helps you see if your margin of safety is growing or shrinking.
What can make your money last longer?
Lower initial withdrawals
Even small reductions in spending can significantly extend portfolio life. Try decreasing spending by 5% and compare results.
Delay Social Security (when appropriate)
For many households, delayed claiming can increase guaranteed lifetime income. That may lower portfolio drawdown later in life.
Use a dynamic withdrawal strategy
Instead of fixed withdrawals, adjust spending after bad market years. Flexible spending often improves retirement sustainability.
Keep a diversified allocation
Asset mix, rebalancing, and risk management all influence long-term outcomes. The return assumption should reflect your real allocation.
Example scenario
Suppose you retire with $1,000,000, spend $5,000/month, receive $2,000/month from Social Security and pension, and expect 5% returns with 2.5% inflation. Your net draw starts at about $3,000/month, then grows over time with inflation. Depending on market performance and future expenses (especially healthcare), this could be sustainable for decades—or require adjustments.
Frequently asked questions
Is this the same as a 4% rule calculator?
Not exactly. The 4% rule is a quick withdrawal benchmark. This tool is more flexible because it includes monthly income, inflation settings, and custom time horizons.
Does this include taxes and required minimum distributions?
No. Taxes, account types, and RMD rules can materially change outcomes. Treat this as a planning estimate and review your plan with a qualified professional.
Can I use this for early retirement?
Yes. If you retire early, increase the projection horizon and test conservative return assumptions. Early retirees are more exposed to inflation and sequence risk due to longer drawdown periods.
Bottom line
A “how long will my money last in retirement calculator” is most useful when you run multiple scenarios—not just one. Try optimistic, base-case, and conservative assumptions. The goal is not a perfect prediction; it’s making better decisions with the best information you have today.