The 4% Rule for Retirement Withdrawals

The 4% rule is a historical retirement-spending guideline: withdraw 4% of the initial portfolio in the first year, then adjust that currency amount for inflation in later years. It is not the same as withdrawing 4% of the current portfolio every year, and it does not guarantee that money will last.

The rule became widely associated with William Bengen’s 1994 research using historical US stock and bond returns. Its usefulness depends on understanding what that research tested and what it left out.

How the 4% calculation works

For the first retirement year:

First-year withdrawal = initial portfolio × 4%

For later years, the previous currency amount is adjusted for inflation. If a €600,000 portfolio begins with a €24,000 withdrawal and inflation is 3%, the second-year amount becomes €24,720.

The table is arithmetic, not a forecast. It does not show whether a particular portfolio could sustain those withdrawals.

What the original research examined

Bengen tested retirement withdrawals against historical US market periods. The analysis considered portfolios of stocks and intermediate-term government bonds and examined how inflation-adjusted withdrawals behaved across different starting dates.

The problem was not average return alone. A retirement beginning before weak markets or high inflation could produce a worse outcome than one beginning in a strong period, even if long-term average returns later appeared similar.

The original article treated historical outcomes as a basis for initial withdrawal decisions. It did not establish a risk-free law, cover every asset class and country, or prove that future market sequences will repeat the US historical record.

Fixed real withdrawals versus a percentage of the balance

Two strategies are often confused:

• Fixed real spending: start with 4% of the original portfolio and adjust the currency amount for inflation.
• Constant percentage spending: withdraw 4% of the current portfolio each year.

The second method automatically cuts withdrawals after portfolio losses and raises them after gains. It reduces depletion risk mechanically, but annual spending can vary sharply. It is not the withdrawal pattern tested by the familiar fixed-real 4% formulation.

Why sequence risk matters

Withdrawals turn early market losses into a different problem from losses during accumulation. Selling assets after a fall leaves fewer units available for a later recovery. Two retirees can earn the same average return but experience different outcomes because returns arrived in a different order.

A constant-return calculator cannot represent sequence risk. It can show the arithmetic relationship between spending, withdrawal rate and portfolio size, but it should not label that result safe.

Inflation is part of the rule

The historical approach was designed to preserve spending power by raising the withdrawal amount with inflation. High inflation therefore increases withdrawals even when markets are weak.

The US Department of Labor notes that retirement costs rise with inflation and that estimates of future income needs must account for the loss of purchasing power. Inflation can also differ across households because healthcare, housing and energy do not necessarily follow a broad consumer-price index.

Why early retirement changes the question

A retirement beginning at 40 may need to fund substantially more than 30 years. Extending the horizon creates more exposure to poor market sequences, inflation, fees and changes in spending.

Financial-independence calculations often use the 4% rate to convert annual expenses into a “FIRE number.” That makes the target easy to understand, but it does not prove the chosen withdrawal rate fits a longer horizon.

The Coast FIRE Calculator is even more assumption-sensitive because it compounds a current portfolio for years before withdrawals begin.

Costs and income the headline rule omits

• Taxes: gross withdrawals may not equal spendable income.
• Investment fees: costs reduce the return available to support withdrawals.
• Public benefits and pensions: these may reduce portfolio withdrawals, but timing and eligibility matter.
• Healthcare and care needs: household inflation can exceed general inflation.
• Portfolio allocation: return and risk depend on the assets held and rebalancing behavior.
• Spending flexibility: reducing optional withdrawals after poor returns changes the strategy.

The Investment Fee Calculator illustrates how recurring investment costs compound over time. A withdrawal plan should use expected returns after applicable fees and taxes.

Use the rule as a disclosed scenario

1. Estimate the annual spending the portfolio must provide.
2. Divide it by 4% to produce a 25-times-spending reference.
3. Repeat the calculation with lower and higher rates to see the sensitivity.
4. Test longer retirement horizons and weaker return or inflation assumptions.
5. Separate core spending from flexible spending.
6. Account for taxes, fees, pensions and public benefits.
7. Review the plan when markets, spending or household circumstances change.

Methodology and limitations

The formulas, table and examples are original Finance Charts arithmetic. The historical description is based on Bengen’s published 1994 article. Finance Charts does not reproduce the paper’s full dataset or claim that historical US outcomes predict future results.

• William P. Bengen — Determining Withdrawal Rates Using Historical Data
• US Department of Labor — Savings Fitness
• Finance Charts — Methodology
• Finance Charts — How Much Money Do You Need to Retire?

Important: The 4% rate is a planning reference derived from historical assumptions. It is not a guaranteed safe withdrawal rate or personalised retirement advice.