How long will my retirement savings last?

TL;DR. At a 4% withdrawal rate, portfolios have historically lasted 30+ years. But real portfolio longevity depends on sequence-of-returns risk, investment fees, and spending flexibility far more than average return. A retirement withdrawal calculator stress-tests your specific balance, spending, and Social Security timing to show whether your money outlasts you — or runs short.

The 4% rule and why it is not enough on its own

The 4% rule originated in William Bengen's 1994 research (later expanded in the Trinity Study). The idea is straightforward: withdraw 4% of your portfolio in the first year of retirement, then adjust that dollar amount for inflation each year. Historically, this approach sustained a 50/50 stock-bond portfolio for at least 30 years in every rolling period since 1926.

Here is a worked example. A retiree with $1,000,000 withdraws $40,000 in year one. With a 2.5% cost-of-living adjustment (the projected 2026 Social Security COLA), year-two withdrawals rise to $41,000. If the portfolio earns 7% nominal but drops 20% in year one, the balance falls to $760,000 before the second withdrawal — and recovery becomes harder because withdrawals continue from a smaller base. This is sequence-of-returns risk, and it is the single biggest threat to portfolio longevity.

Adjusted for current equity valuations (CAPE ratio above 30), some financial planners now recommend a 3.5% initial withdrawal rate rather than 4%. On $1,000,000, that is $35,000 versus $40,000 — a $5,000 annual difference that can add 5-7 years of portfolio life in a poor-return environment.

A safe withdrawal calculator makes this concrete by modeling your specific balance, withdrawal rate, expected returns, and the sequence risk that averages hide.

Try it with your numbers

What a good withdrawal longevity calculator should show

• Year-by-year portfolio balance projection through age 95 or 100.
• The specific age at which the portfolio reaches zero under the chosen withdrawal rate.
• Sensitivity analysis showing how different return assumptions change the depletion date.
• The impact of delaying or accelerating Social Security on total portfolio drawdown.
• Inflation-adjusted spending in future dollars so the retiree sees real purchasing power. AdvisorCal's Withdrawal Longevity Calculator handles all of the above. Combine it with the Retirement Readiness Calculator to see whether you are saving enough before retirement, or the Roth Conversion Calculator to model tax-efficient drawdown strategies.

Key facts

• 4% rule origin: William Bengen's 1994 research, expanded by the 1998 Trinity Study.
• Historical success rate: a 4% initial withdrawal from a 50/50 portfolio survived 30 years in roughly 95% of historical periods.
• Adjusted safe rate (2026 context): 3.5% is increasingly cited given elevated equity valuations.
• Sequence-of-returns risk window: the first 5-10 years of retirement matter most; a bear market early on does far more damage than one in year 20.
• 2026 Social Security COLA: approximately 2.5%.
• Average retirement length: a 65-year-old couple has a 50% chance that one spouse lives past 90 — plan for 25-30 years minimum.

Common follow-ups

What happens if I withdraw more than 4%? Higher withdrawal rates compress portfolio life sharply. At 5%, the historical failure rate (running out of money in 30 years) jumps from roughly 5% to about 15-20%. At 6%, failure exceeds 30%. A portfolio longevity calculator shows the exact year your balance hits zero at each rate, which is far more useful than a generic rule of thumb.

Does the 4% rule account for Social Security income? No. The 4% rule applies only to the investable portfolio. Social Security is additive. If you need $60,000 per year and Social Security provides $24,000, you only need $36,000 from the portfolio — a 3.6% rate on $1,000,000. This is why optimizing your Social Security claiming age directly affects how long your 401(k) lasts.

How do fees affect portfolio longevity? A 1% annual advisory or fund fee on a $1,000,000 portfolio costs $10,000 in year one and compounds over time. Over 30 years, a 1% fee drag can reduce the terminal portfolio value by 25-30%. The calculator lets you input your actual fee rate so the projection reflects what you keep, not what the market returns.

Should I use the 4% rule or the 3.5% rule? It depends on your flexibility. If you can reduce spending in down markets (a "guardrails" approach), 4% is reasonable. If your spending is fixed — mortgage, insurance, healthcare — a 3.5% starting rate provides a larger cushion. A safe withdrawal calculator lets you test both scenarios side by side.

When this doesn't apply

The 4% rule and withdrawal longevity projections assume a diversified stock-and-bond portfolio. They do not apply to annuitized income (which is guaranteed by the insurer, not by the portfolio), real-estate-heavy portfolios where cash flow depends on tenants and property values, or situations where a retiree has a pension covering most living expenses. In those cases, portfolio drawdown is a secondary concern and the planning question shifts to liquidity and legacy rather than depletion risk.

Sources

• Bengen, W. "Determining Withdrawal Rates Using Historical Data," Journal of Financial Planning, 1994
• Trinity Study (Cooley, Hubbard, Walz), AAII Journal, 1998

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