The 4% rule, from William Bengen's 1994 research, states that you can withdraw 4% of your initial portfolio in year 1, then adjust for inflation annually, and the portfolio will last at least 30 years with high probability. Based on a 50/50 stock/bond portfolio and historical US market data, this rule survived all 30-year historical periods from 1926 to the present, including the Great Depression and 1970s inflation.

Retirement Withdrawal Calculator

Q: How long will $1 million last in retirement?

At a 4% annual withdrawal ($40,000/year or $3,333/month) with a 5% annual return: $1 million will last indefinitely (the return exceeds withdrawals). At zero return, $1 million lasts 25 years at $40,000/year. At a 6% withdrawal ($60,000/year) with 5% return: approximately 28 years. The key is the relationship between the withdrawal rate and the portfolio return.

Q: What withdrawal rate is safe for early retirement?

For a 30-year retirement (retiring at 65 with 95 life expectancy), 4% is the widely cited safe rate. For a 40-year retirement (retiring at 55), 3.5% is more conservative. For a 50-year retirement (retiring at 45, FIRE), 3–3.25% is often recommended. The longer the retirement horizon, the more sequence-of-returns risk there is - a market crash early in retirement can permanently impair a portfolio's longevity.

Find out how long your retirement savings will last - or how much you can safely withdraw.

💸 How Long Will Your Retirement Savings Last?

One of the most critical questions in retirement planning is: how long will my money last? The answer depends on three variables: how much you have (portfolio balance), how much you spend (monthly withdrawal), and how much your investments earn (return rate) during the withdrawal phase. This calculator solves this question directly - given a balance and monthly withdrawal at a given return rate, it computes the number of years until the portfolio is depleted.

The 4% rule provides a widely-used benchmark: withdrawing 4% of the initial portfolio annually has historically sustained a 30-year retirement through all market cycles, including the Great Depression and 1970s stagflation. For a $1 million portfolio, this translates to $40,000/year or $3,333/month. Early retirees who need 40–50 years of income often use 3–3.5% to improve sustainability. Conversely, short retirement horizons (10–15 years) can support higher rates (6–8%).

Sequence-of-returns risk - the risk of poor investment returns early in retirement - is the biggest threat to portfolio longevity. A market crash in the first 5 years of retirement can permanently impair a portfolio even if long-run returns recover. This is why most retirement financial planning uses conservative return assumptions (4–5%) during the withdrawal phase rather than the historical 7–10% average.

📐 Portfolio Longevity Formula

n = −ln(1 − PV × r / PMT) / ln(1 + r)

4% Rule Monthly = Balance × 4% / 12

n = Number of months until depletion

PV = Current portfolio balance

r = Monthly return rate (annual / 12)

PMT = Monthly withdrawal amount

This is the standard present-value annuity formula solved for n (number of periods). If PMT ≤ PV × r (monthly withdrawal doesn't exceed monthly earnings), the portfolio lasts indefinitely - your withdrawal rate is at or below the perpetuity threshold. When this condition holds, the portfolio never depletes; it shows as "Indefinite" in the calculator.

📖 How to Use This Calculator

Steps

Enter your portfolio balance - total of all retirement accounts, brokerage accounts, and other investments.

Enter monthly withdrawal - your planned monthly spending from the portfolio (exclude Social Security and pension income, which are separate).

Enter expected return rate - use 4–6% for a balanced portfolio in retirement (more conservative than accumulation phase assumptions).

Click Calculate to see how many years the portfolio lasts, the 4% rule monthly safe amount, and your annual withdrawal rate.

💡 Example Calculations

Example 1 - $1M Portfolio, $4,000/month

Balance = $1,000,000 | Monthly = $4,000 | Return = 5%

Monthly rate r = 5/12/100 = 0.4167%; PMT = $4,000; PV = $1,000,000

n = −ln(1 − 1,000,000 × 0.004167 / 4,000) / ln(1.004167) = −ln(1 − 1.0417) / ... = indefinite (portfolio earns more than withdrawal)

4% rule monthly = $1M × 4% / 12 = $3,333/month | Annual rate = 4.8% - slightly above 4% SWR

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Example 2 - $500K Portfolio, $3,500/month

Balance = $500,000 | Monthly = $3,500 | Return = 5%

Annual withdrawal = $42,000 = 8.4% of $500K - well above 4% SWR. Portfolio lasts approximately 17 years

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❓ Frequently Asked Questions

How long will $1 million last in retirement?+

At a 4% annual withdrawal ($40,000/year) with a 5% annual return, $1 million will last indefinitely (return exceeds withdrawals). At zero return, it lasts 25 years. At a 6% withdrawal ($60,000/year) with 5% return: approximately 28 years. The key is the relationship between the withdrawal rate and portfolio return.

What is the 4% rule?+

The 4% rule states you can withdraw 4% of your initial portfolio in year 1, adjust for inflation annually, and the portfolio will last at least 30 years. Based on a 50/50 stock/bond portfolio and historical US market data, this rule survived all 30-year periods from 1926 onward, including the Great Depression and 1970s inflation.

What withdrawal rate is safe for early retirement?+

For a 30-year retirement: 4%. For a 40-year retirement: 3.5%. For a 50-year retirement (FIRE): 3–3.25%. The longer the retirement, the more sequence-of-returns risk exists - a market crash early in retirement can permanently impair portfolio longevity.

How do I calculate a sustainable monthly withdrawal?+

Sustainable monthly withdrawal = Portfolio Balance × Annual SWR / 12. For $800,000 at 4% SWR: $800,000 × 4% / 12 = $2,667/month. This maintains the real purchasing power of the portfolio over 30 years in most historical scenarios.