Retirement Withdrawal Rate Calculator

Where the 4% Rule came from

William Bengen, a financial advisor, published his seminal 1994 paper in the Journal of Financial Planning titled “Determining Withdrawal Rates Using Historical Data.” He tested every historical 30-year period in US market history (using actual returns and inflation from 1926-1992) and found that retirees could withdraw 4% of their initial portfolio in year one, adjust for inflation each year, and never run out of money in any historical 30-year window.

His finding was originally cautious — the “SAFEMAX” withdrawal rate. Subsequent research by the Trinity Study (Cooley, Hubbard, Walz, 1998) confirmed and refined the 4% number, and it became known as the 4% Rule.

The basic math:

Annual Withdrawal Year 1 = Portfolio × 4% Annual Withdrawal Year N = Year 1 amount × (1 + inflation)^(N-1)

For a $1,000,000 portfolio:

• Year 1: $40,000
• Year 2 (3% inflation): $41,200
• Year 3: $42,436
• Year 30 (3% avg inflation): $94,000

The portfolio assumption: 60/40 stocks/bonds

The 4% Rule assumes a portfolio of roughly 60% stocks and 40% bonds, rebalanced annually. This is the classic “balanced retirement portfolio” allocation. Different allocations produce different safe rates:

The interesting finding: higher stock allocation doesn’t necessarily increase safe rate. The volatility actually hurts the 4% Rule due to “sequence of returns risk.”

Sequence of returns risk — the silent retirement killer

The order of returns matters enormously. Consider two retirees with identical 30-year average returns of 7%:

Retiree A: high returns first, then losses later

• Year 1-5: +15% per year
• Year 26-30: -5% per year
• Portfolio mostly grows before withdrawals matter

Retiree B: losses first, then high returns

• Year 1-5: -5% per year
• Year 26-30: +15% per year
• Portfolio depleted by combined withdrawals + losses early

Same average return, but B runs out of money far earlier. This is sequence of returns risk. The 4% Rule survived because Bengen tested the worst historical sequences (early 1930s and 1965-1969 retirements were the closest to failure).

How the 4% Rule survives bad markets

Specific historical retirement years and their 30-year outcomes at 4%:

The 4% Rule has never failed in US historical data with a 60/40 portfolio over 30 years. But many critics worry it may not survive the next few decades because of:

• Lower expected bond returns (current yields lower than 1980s-2010s)
• Stock valuations near historical highs (lower expected forward returns)
• Higher inflation than the 2010s
• Longer retirements (people living to 90s+)

Modern revisions: 3.3-3.7% rule

In response to concerns about future returns, recent research suggests lower safe rates:

• Morningstar 2021 research: 3.3% for newly retiring 30-year retirements
• Big ERN’s safe withdrawal series: 3.25-3.75% for various confidence levels
• Wade Pfau and Michael Kitces: 3.5-4.0% depending on starting valuations

The honest reality: for new retirees starting in 2024-2025, 3.5-3.8% is more defensible than 4%.

Variable spending strategies — beating the 4% Rule

Rigid 4% spending isn’t actually how retirees should behave. Modern research favors variable spending:

Guardrails (Kitces 2015):

• Start at 5.0% withdrawal rate
• If portfolio drops 20% from initial, cut spending by 10%
• If portfolio rises 20%, increase spending by 10%
• Provides more income in good years, less in bad years
• Historical success rate at 5% with guardrails: 95%+

RMD-style (similar to required minimum distributions):

• Each year, withdraw 1 ÷ life expectancy years of current portfolio
• 65-year-old: 1÷20 = 5%
• 75-year-old: 1÷13 = 7.7%
• 85-year-old: 1÷7 = 14.3%
• Always responsive to current portfolio; never depletes
• But spending varies a lot year-to-year

Vanguard’s “dynamic” approach:

• Floor: never less than year-1 amount adjusted for inflation
• Ceiling: never more than initial × 1.5 (real)
• Adjust within range based on portfolio performance

These approaches allow higher average spending (~5%) while maintaining sustainability.

The Sustainable Withdrawal Rate by retirement length

The 4% Rule assumes 30 years. Different time horizons need different rates:

Early retirees (FIRE community) typically aim for 3.5% or lower withdrawal rates because of the long horizon. Late retirees (starting at 70+) can use 5%+ with reasonable safety.

Social Security and pensions change everything

The 4% Rule treats your investment portfolio as your only income. In reality, most US retirees have:

• Social Security ($1,500-$4,500/month for typical earners)
• Pensions (if employer offers)
• Rental income (some retirees)
• Part-time work (especially early years)

If Social Security covers $2,500/month ($30,000/year) of your $80,000/year expenses, you only need to withdraw $50,000/year from investments. With a $1M portfolio, that’s 5% — well above 4%. The “income gap” matters more than the absolute spending.

The withdrawal order matters

In tax-efficient retirement, the order of withdrawal accounts matters:

1. Required Minimum Distributions (RMDs) from traditional 401(k)/IRA — required starting age 73+
2. Taxable accounts (brokerage): use long-term capital gains rates
3. Tax-deferred (traditional IRA, 401(k)): use proportionally to manage tax brackets
4. Roth IRA/401(k): save for last (tax-free growth)
5. HSA: keep for medical expenses (triple tax advantage)

Smart withdrawal sequencing can save tens of thousands in taxes over a retirement.

The healthcare wild card

Healthcare costs in retirement are a major risk:

• Medicare doesn’t cover everything (Part B/D premiums, copays, dental, hearing, vision)
• Long-term care can devastate a retirement (covered by neither Medicare nor most insurance)
• Healthcare cost inflation runs 4-6%/year (higher than general inflation)

Fidelity’s 2024 estimate: a 65-year-old couple needs $315,000 for healthcare costs through retirement (excluding long-term care). This should be considered separately from the basic 4% Rule.

Bottom line

The 4% Rule is a 30-year retirement guideline using 60/40 stocks/bonds, validated against historical US data. For new retirees today, 3.5-3.8% is more defensible given current market conditions. Sequence of returns risk makes the first 5-10 years of retirement critical. Variable spending strategies (guardrails) allow higher average withdrawal with maintained safety. Social Security and pensions reduce the burden on investment portfolios. Healthcare and long-term care should be planned separately.