FIRE Strategy

The 4% Rule: Is the Classic FIRE Guideline Still Safe in 2025?

January 16, 2025
15 min read

The 4% rule has been the holy grail of FIRE planning for decades. But with inflation hitting 40-year highs, bond yields fluctuating wildly, and market valuations at historic levels, is this 30-year-old rule still reliable? Let's dive deep into the data.

The Uncomfortable Truth

Recent studies suggest the 4% rule might only have a 75-85% success rate in current market conditions—down from the historical 95% success rate. Here's what every FIRE planner needs to know.

What Exactly Is the 4% Rule?

The 4% rule, developed by financial planner William Bengen in 1994, states that you can safely withdraw 4% of your portfolio in the first year of retirement, then adjust that amount for inflation each subsequent year, without running out of money for 30 years.

The Classic 4% Rule Formula

  • FIRE Number: Annual Expenses × 25
  • Safe Withdrawal: Portfolio Value × 4%
  • Example: $40,000 expenses = $1,000,000 FIRE number

The Original Study: What Made It Work

Bengen's research was based on historical data from 1926-1976, testing various withdrawal rates across different 30-year periods. His findings:

Withdrawal RateSuccess RateWorst Case Scenario
3%100%Portfolio grew
4%95%Portfolio lasted 30+ years
5%75%Ran out after 20 years

Why 2025 Is Different: The New Challenges

1. The CAPE Ratio Problem

The Cyclically Adjusted Price-to-Earnings (CAPE) ratio is currently around 30—well above the historical average of 17. High CAPE ratios historically predict lower future returns.

Historical CAPE vs Returns

  • • CAPE 10-15: ~10% annual returns
  • • CAPE 20-25: ~7% annual returns
  • • CAPE 25-30: ~5% annual returns
  • • CAPE 30+: ~3% annual returns

Impact on 4% Rule

  • • Lower returns = higher failure risk
  • • Sequence of returns risk increases
  • • Early retirement years most vulnerable
  • • May need 3-3.5% withdrawal rate

2. The Bond Yield Dilemma

The original 4% rule assumed a 60/40 stock/bond portfolio. But with bonds yielding near historic lows for over a decade, the traditional portfolio balance is under stress.

3. Inflation's Comeback

The 4% rule was tested during a period of relatively stable inflation. With inflation volatility returning, the real purchasing power of withdrawals becomes unpredictable.

Modern Research: What the Latest Studies Show

2023 Morningstar Study Results

Based on current market conditions and forward-looking projections:

  • 4% withdrawal rate: 75% success probability
  • 3.8% withdrawal rate: 80% success probability
  • 3.3% withdrawal rate: 90% success probability

Alternative Strategies for 2025

1. The Dynamic Withdrawal Strategy

Instead of fixed 4%, adjust withdrawals based on portfolio performance and market conditions:

  • Good market years: Withdraw 4-4.5%
  • Average years: Withdraw 3.5-4%
  • Poor market years: Withdraw 2.5-3%

2. The Bond Tent Approach

Gradually increase bond allocation as you approach and enter retirement to reduce sequence of returns risk.

3. The Bucket Strategy

Divide your portfolio into time-based buckets: 1-3 years (cash/bonds), 4-10 years (balanced), 10+ years (growth stocks).

Test Your FIRE Plan Against Reality

The 4% rule is just one scenario based on historical averages. But what if you retire into a bear market? What if inflation spikes? What if bonds underperform for a decade?

Our Monte Carlo simulation runs thousands of different market scenarios to show you the probability of success for YOUR specific plan. Don't rely on rules of thumb when your financial independence is at stake.

Practical Recommendations for 2025

Conservative Approach

  • • Use 3-3.5% withdrawal rate
  • • Build larger FIRE number (28-33x expenses)
  • • Include part-time income flexibility
  • • Maintain higher cash reserves

Moderate Approach

  • • Start with 3.5-4% withdrawal rate
  • • Use dynamic withdrawal adjustments
  • • Plan for geographic arbitrage
  • • Build multiple income streams

The Bottom Line

The 4% rule isn't dead, but it's not the ironclad guarantee it once seemed. In today's market environment, a more conservative 3.5% withdrawal rate or dynamic strategy might be prudent. The key is understanding that any rule is just a starting point—your actual plan should account for your specific circumstances, risk tolerance, and market conditions.

Remember: FIRE isn't just about reaching a number—it's about maintaining financial independence for decades. Better to be conservative and secure than aggressive and sorry.