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Target Date Withdrawal

Calculate level withdrawals that will fully deplete your portfolio by your target age, like a mortgage in reverse.

How It Works​

Target Date Withdrawal treats your retirement portfolio as a finite resource and uses standard amortization math to compute the largest level payment you can sustain until a chosen end date. It is the same formula a bank uses to calculate your mortgage payment — except here, you are the bank paying yourself.

You specify a target age (typically your life expectancy), an assumed rate of return, and your current portfolio balance. The formula then produces an annual withdrawal amount that, if returns match your assumption, will bring the portfolio to exactly zero at your target date. Each year the calculation is refreshed with the actual portfolio balance and remaining years, so withdrawals automatically adjust to real market performance.

The strength of this method is that it maximizes your spending potential — you are not leaving money on the table by planning for an unrealistically long horizon. The risk is equally clear: if you live past your target date, the money is gone. This makes Target Date most appropriate for retirees with other guaranteed income that covers basic needs, or as one component in a multi-strategy approach.

The Formula​

Each year (recalculated):

remainingYears = targetAge - currentAge
rate = expectedAnnualReturn

withdrawal = portfolio × rate / (1 - (1 + rate)^(-remainingYears))

This is the standard PMT (payment) formula from financial mathematics.

Key parameters:

  • Target age: The age at which you want the portfolio to reach zero (e.g., life expectancy)
  • Expected return: Assumed annual portfolio return for the calculation
  • Portfolio balance: Recalculated each year with actual returns

Pros & Cons​

Advantages:

  • Maximizes total spending potential over the specified horizon
  • Clear, understandable end date for planning
  • Simple amortization math that is widely understood
  • Automatically adjusts when recalculated annually with actual balances

Limitations:

  • Real risk of outliving the money if you exceed your target age
  • Depends heavily on the return assumption — overestimate and you deplete early
  • No safety buffer for unexpected expenses or longevity
  • Psychologically difficult to watch the portfolio approach zero by design

Example​

Starting portfolio: $1,000,000 | Starting age: 65 | Target age: 90 | Assumed return: 5%

AgePortfolioRemaining YearsWithdrawal
65$1,000,00025$70,952
70$870,00020$69,840
75$700,00015$67,436
80$490,00010$63,461
85$240,0005$55,440
90$00—

Withdrawals start high and decline modestly as the portfolio shrinks. By age 90 the portfolio is fully depleted as designed. If markets outperform the 5% assumption, withdrawals rise; if they underperform, withdrawals fall.

When to Use This Method​

Target Date Withdrawal works best for retirees who:

  • Have guaranteed income (Social Security, pension, annuity) covering essential expenses
  • Want to maximize discretionary spending from their investment portfolio
  • Are comfortable planning to a specific life expectancy
  • Use this as one layer in a multi-strategy retirement plan

It is less suitable for retirees with no other income sources, those with strong longevity in their family, or anyone who would find a declining portfolio balance psychologically stressful.

Try It Yourself

Compare Target Date against other strategies using your own numbers in the Scenario Builder.

References​