What Is the 4% Rule? Safe Withdrawal Rates for Retirement

The 4% rule is the most widely cited guideline for how much you can withdraw from a retirement portfolio each year without running out of money over a 30-year retirement. Withdraw 4% of your portfolio's starting value in Year 1, then increase that amount by inflation each year, and your portfolio has historically lasted 30+ years.

It is both a planning tool (how much do I need to retire?) and a spending rule (how much can I take out each year?). It links directly to the FIRE movement's 25× rule: 25 × annual expenses = retirement portfolio target (because $1 ÷ 4% = 25×).

Where Does the 4% Rule Come From?

The rule comes from the 1994 Trinity Study by three professors at Trinity University. They back-tested a range of stock/bond portfolios and withdrawal rates across every 30-year period from 1926 to 1995 using historical US market data.

Their key finding: a portfolio of 50–75% stocks withdrew at 4%/year survived 95–100% of all 30-year periods in the historical record, even when retirement started just before a major crash.

The 4% rate was the highest rate that survived virtually all historical scenarios — not just average ones.

How It Works in Practice

Suppose you retire with $1,000,000:

Year	Portfolio start	Withdrawal	Portfolio end (7% return, 3% inflation)
1	$1,000,000	$40,000 (4%)	~$1,030,000
2	~$1,030,000	$41,200 (+3% inflation)	~$1,062,000
5	~$1,125,000	$45,000	~$1,160,000
10	~$1,310,000	$52,000	~$1,350,000
30	~$1,800,000+	$97,000	~$1,750,000+

In a favourable scenario, the portfolio actually grows despite withdrawals. In bad scenarios (low returns early in retirement), it can dip significantly before recovering.

Use the Safe Withdrawal Rate Calculator to model your own portfolio with any withdrawal rate and return assumptions.

Is 4% Still Safe?

This is actively debated. Arguments for a lower rate (3–3.5%):

• Today's bond yields are lower than the 1926–1995 period used in the Trinity Study
• Early retirees (FIRE movement) need 40–50 year horizons, not 30
• Current equity valuations may imply lower future returns
• Healthcare inflation runs above general CPI

Arguments for keeping 4%:

• The rule has survived every 30-year historical period including the Great Depression, 1970s stagflation, and the dot-com crash
• Modern portfolios can include international stocks, REITs, and inflation-protected bonds
• Many retirees adjust spending in down years (dynamic withdrawal)

Practical guidance: 4% is a reasonable starting point for a 30-year retirement. For early retirees (retiring before 55), use 3–3.5%.

Sequence-of-Returns Risk

The biggest danger to the 4% rule is sequence-of-returns risk — getting bad returns in the early years of retirement while still making large withdrawals.

Consider two retirees both averaging 7% returns over 20 years:

• Retiree A gets +20%, +15%, +10% in years 1–3, then -10%, -5%, -15% later
• Retiree B gets -10%, -5%, -15% in years 1–3, then +20%, +15%, +10% later

Retiree B's portfolio ends up much smaller despite identical average returns, because the early losses compound on a shrinking base while withdrawals continue.

Mitigation strategies:

• Keep 1–2 years of expenses in cash to avoid selling during crashes
• Use a flexible withdrawal strategy (cut spending by 10% in down years)
• Consider a bond tent — holding more bonds early in retirement, shifting to stocks later

Dynamic Withdrawal Strategies

The traditional 4% rule is a fixed rule. More sophisticated approaches adapt to market conditions:

Strategy	How it works
Guyton-Klinger	Increase/decrease withdrawals based on portfolio performance guardrails
Kitces ratchet	Increase spending after strong years; never decrease
RMD method	Base annual withdrawal on IRS Required Minimum Distribution tables
Floor-and-upside	Fund non-discretionary expenses with annuities; take variable withdrawals from the rest

Dynamic strategies typically allow higher average spending than a fixed 4% rule because they share some risk with the market.

Key Takeaways

• 4% is a historical benchmark — not a guarantee
• It was designed for a 30-year retirement with a diversified US stock/bond portfolio
• Early retirees should plan on 3–3.5%
• Sequence-of-returns risk matters more than average returns
• Flexibility in spending dramatically improves sustainability

For the FIRE-planning side of the equation, see the FIRE Number Calculator and the Coast FIRE Calculator.