Inflation-adjusted spending is the classic 4% rule implementation: withdraw a fixed real (inflation-adjusted) amount each year regardless of portfolio performance. It provides predictable income but ignores market conditions entirely - making it riskier than dynamic strategies that adapt to downturns.
Inflation-adjusted spending is a retirement withdrawal strategy where the initial withdrawal amount increases each year by the rate of inflation, maintaining constant purchasing power throughout retirement. This is the classic implementation of the 4% rule - you set your spending level once, and it never changes in real terms.
How It Works
- Year 1: Choose an initial withdrawal amount (e.g., 4% of your starting portfolio)
- Each subsequent year: Increase the withdrawal by the actual inflation rate
- Ignore portfolio performance: Whether markets are up 30% or down 30%, your withdrawal stays on the same inflation-adjusted track
Example with 1,000,000 portfolio at 4% initial rate:
| Year | Inflation | Withdrawal | In Today's Money |
|---|---|---|---|
| 1 | - | 40,000 | 40,000 |
| 2 | 3% | 41,200 | 40,000 |
| 3 | 3% | 42,436 | 40,000 |
| 5 | 3% | 45,020 | 40,000 |
| 10 | 3% | 52,191 | 40,000 |
The real spending power stays flat at 40,000 (in today's money) for the entire retirement.
Why It Matters for Retirement Planning
Inflation-adjusted spending has a unique combination of strengths and weaknesses:
Strengths:
- Predictable income: you always know exactly what you can spend, adjusted for cost of living
- Simple to implement: no calculations, no monitoring, no decisions
- Proven track record: historically survived most 30-year periods with a 4% starting rate
Weaknesses:
- Ignores portfolio performance: withdrawing the same amount during a market crash accelerates depletion - this is the core of sequence-of-returns risk
- No upside participation: even if your portfolio doubles, your spending stays flat
- Vulnerable to high inflation: a spike in inflation increases withdrawals precisely when markets are often performing poorly
This rigidity is why the strategy has a lower success rate than dynamic alternatives like Guyton-Klinger or floor & ceiling in Monte Carlo simulations.
Inflation-Adjusted Spending in Retirement Lab
Inflation-adjusted spending is Retirement Lab's default strategy, on the free plan too: you enter your monthly spending in today's money, and it rises with inflation every year, whatever the portfolio does.
This makes it an ideal baseline for comparison: run a simulation with inflation-adjusted spending first, then switch to a dynamic strategy to see how much the success rate improves when spending adapts to market conditions.
How Retirement Lab Addresses This
Retirement Lab models inflation-adjusted spending as its baseline withdrawal strategy, increasing your withdrawal amount each year by the inflation rate you configure. Run a simulation to see how inflation erosion affects your success rate over 30+ years.
Frequently Asked Questions
- What is the difference between inflation-adjusted spending and the 4% rule?
- They are essentially the same thing. The 4% rule IS an inflation-adjusted spending strategy - you withdraw 4% of your initial portfolio in year one, then increase that amount by inflation each year. The term 'inflation-adjusted spending' describes the mechanism; '4% rule' describes the specific withdrawal rate.
- What happens if inflation is higher than expected?
- With inflation-adjusted spending, your withdrawals increase with actual inflation regardless of portfolio performance. If inflation spikes (like the 8-9% seen in 2022), your withdrawals rise sharply while your portfolio may be flat or declining. This combination accelerates portfolio depletion and is one of the strategy's key risks.
- Should I use inflation-adjusted spending or a dynamic strategy?
- Inflation-adjusted spending provides stable, predictable income but is riskier for the portfolio. Dynamic strategies like Guyton-Klinger trade income stability for dramatically better portfolio survival rates. If you have flexible expenses and can tolerate income variability, a dynamic strategy is generally superior.