Tool · Investor Sam Retirement

Will My Money Last? Longevity Drawdown Simulator

July 1, 2026 • By the Investor Sam Editorial Team • Reviewed by Berly Sam Varghese, Editor
The 4% rule is a starting point, not a guarantee. This simulator runs your specific numbers year by year — spending, inflation, and real returns — to answer the question retirees lose sleep over: will the money last? Enter your portfolio, annual spend, and expected lifespan, and the tool tells you either the remaining balance at your target age or the age your money runs out.

Example: Portfolio at retirement: 1000000 $ · Annual spending in retirement: 50000 $ · Expected annual portfolio return: 6 % · Inflation rate: 3 % · Retirement age: 65 · Target age to fund through: 90

Remaining balance at target age$628,383
Your initial withdrawal rate5.00%
Portfolio depletes before target age (1=yes, 0=no)0
Age portfolio runs out (0 = survives)0

Worked example

A $1,000,000 portfolio with $50,000 annual spend (5% withdrawal rate), 6% return, and 3% inflation simulated from age 65 to 90 leaves approximately $627,000 at age 90 — the portfolio survives. But at $70,000 spend (7% rate), the same portfolio runs out around age 83, seven years too soon.

Frequently asked questions

What is a safe withdrawal rate?

The original 1994 Bengen study identified 4% as a rate that historically survived 30-year retirements in diversified US portfolios. Subsequent research suggests 3.3%–4.5% varies by portfolio allocation, sequence of returns, and retirement length. Longer retirements (35+ years) warrant lower initial rates.

Does this account for Social Security income?

Enter your net spending after Social Security and any pension income. If SS covers $24,000/year and you need $60,000, enter $36,000 as annual spending — the portfolio only needs to fund the gap.

What return should I use?

A 60/40 stock-bond portfolio has historically returned about 6.5%–7% nominal, or 3.5%–4.5% real (after inflation). For a conservative simulation, use 5–6% nominal with 3% inflation. Adjust based on your allocation.

What happens if my portfolio depletes early?

If the balance hits zero before your target age, the calculator flags the depletion age. Solutions include: reducing spending, delaying retirement, converting a portion to an annuity, taking Social Security later, or working part-time in early retirement.

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Sources

Berly Sam Varghese · Editor, Investor Sam

Berly Sam Varghese is an engineer who treats money the way he treats any hard problem — something to be engineered, not gambled on. He funded years of education and built real financial stability the patient way, by living below his means and investing rather than borrowing. He writes for the person afraid they started saving too late. He reviews and approves every article on Investor Sam and checks the figures against primary sources before anything is published. More about our standards.