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Fixed Percentage of Portfolio

Withdraw a fixed percentage of your current portfolio value each year, so the dollar amount rises and falls with the market.

How It Works​

The Fixed Percentage method recalculates your withdrawal every year based on what your portfolio is actually worth. If you choose 4% and your portfolio is $1,000,000, you withdraw $40,000. If the market drops and your portfolio falls to $800,000, you withdraw $32,000. If it rises to $1,200,000, you withdraw $48,000.

This is fundamentally different from the 4% Rule, which sets a dollar amount in Year 1 and then adjusts only for inflation. The Fixed Percentage method recalculates from scratch each year using the current portfolio balance. The percentage stays constant; the dollar amount fluctuates.

The mathematical advantage is significant: your portfolio can never reach zero. You are always taking a fraction of what remains, so there will always be something left (in theory). The practical disadvantage is equally significant: your income is volatile. A 30% market crash means a 30% pay cut. For retirees who depend on portfolio withdrawals to cover fixed expenses like housing and healthcare, this volatility can be difficult to manage.

The Formula​

Each year:

withdrawal = currentPortfolio × percentage

Key parameters:

  • Withdrawal rate: The fixed percentage applied each year (e.g., 4%)
  • Recalculation: Annual, based on current portfolio value

Pros & Cons​

Advantages:

  • Portfolio mathematically cannot be fully depleted
  • Simple calculation — one multiplication per year
  • Automatically adjusts to market conditions (spend more after good years, less after bad)
  • No sequence-of-returns risk in the traditional sense

Limitations:

  • Volatile year-to-year income — income swings match market swings
  • Income drops sharply during bear markets, exactly when retirees may feel most anxious
  • Difficult to budget when income is unpredictable
  • No guaranteed minimum withdrawal amount
  • After prolonged downturns, the dollar amount may not recover to previous levels for years

Example​

Starting portfolio: $1,000,000 | Fixed percentage: 4% | Varying market returns

YearPortfolio (start)Market ReturnWithdrawalChange from Year 1
1$1,000,000—$40,000—
2$1,020,000+6%$40,800+2%
3$850,000-20%$34,000-15%
4$870,000+7%$34,800-13%
5$1,100,000+18%$44,000+10%
10$1,250,000(cumulative)$50,000+25%

Notice the whiplash between Years 2 and 3: a single bad year cuts income by 17%. This is the core trade-off — the portfolio is safe, but income stability is sacrificed.

When to Use This Method​

The Fixed Percentage method works best for retirees who:

  • Have substantial guaranteed income (Social Security, pension) covering essential expenses
  • Can treat portfolio withdrawals as discretionary "bonus" income
  • Have flexible spending that can absorb 20-30% swings
  • Prioritize portfolio longevity over income stability

Consider a guardrail method (like Guyton-Klinger or Floor-Ceiling) if you want some of the adaptive benefits of percentage-based withdrawals but with limits on how much your income can swing in any given year.

Try It Yourself

Compare Fixed Percentage against other strategies using your own numbers in the Scenario Builder.

References​