Retirement Planning: Estimating What You May Need for the Future

One of the central questions in retirement planning is deceptively simple: How much money will I need to retire?

There is no universal retirement savings number that works for every household. A target such as $1 million can mean very different things depending on housing costs, healthcare expenses, taxes, Social Security benefits, desired lifestyle, retirement age, investment returns, and longevity.

A more useful approach is to build a retirement income estimate from expected expenses and available income sources, then test whether your investment portfolio can reasonably support the gap.

Start With Your Expected Retirement Expenses

The foundation of retirement planning is an estimate of how much you expect to spend after leaving the workforce.

Rather than assuming expenses will automatically fall, divide your current spending into categories and determine which costs are likely to change.

Housing Costs

Housing can represent a substantial portion of retirement spending.

If a mortgage is expected to be fully paid before retirement, monthly expenses may decline. However, homeowners still need to account for:

• Property taxes
• Homeowners insurance
• Maintenance and repairs
• Utilities
• HOA fees
• Major replacements

Renters should account for the possibility of changing rent costs over a long retirement period.

Healthcare Expenses

Healthcare deserves separate attention because Medicare does not eliminate all medical spending.

Retirees may still face Medicare premiums, deductibles, coinsurance, prescription costs, supplemental coverage, dental and vision expenses, and long-term care costs.

Healthcare spending can also vary significantly from one household to another, making it difficult to estimate using a single percentage of pre-retirement income.

Lifestyle Spending

Retirement spending can change over time.

Some retirees spend more during their early retirement years on travel, hobbies, entertainment, and other activities. Spending may later change as lifestyle patterns evolve.

Creating separate estimates for early, middle, and later retirement can therefore provide a more realistic planning framework than assuming expenses remain constant.

Account for Social Security and Other Retirement Income

Investment accounts are only one part of a retirement-income plan.

Potential income sources can include:

• Social Security benefits
• Pension income
• 401(k) distributions
• Traditional IRA withdrawals
• Roth IRA distributions
• Taxable brokerage assets
• Rental income
• Annuity income
• Part-time employment

The amount your investment portfolio needs to provide depends heavily on how much reliable income comes from other sources.

For example, a household expecting $40,000 per year from Social Security and requiring $70,000 in annual retirement spending has a substantially different portfolio requirement from a household needing the full $70,000 from investments.

The 25x Rule and Withdrawal Rates

The Rule of 25 is a commonly discussed retirement-planning shortcut based on dividing desired annual portfolio withdrawals by 4%.

For example:

$60,000 ÷ 0.04 = $1.5 million

The calculation produces a $1.5 million portfolio target.

However, the 25x rule should not be treated as a guarantee that $1.5 million will safely fund every 30-year retirement.

Historical withdrawal-rate research has examined different asset allocations, market periods, withdrawal patterns, inflation assumptions, and retirement durations. Results vary depending on the methodology and assumptions used.

A fixed 4% withdrawal rate also does not automatically account for taxes, investment fees, changing spending needs, Social Security timing, healthcare expenses, or a retirement lasting longer than 30 years.

For these reasons, the 4% figure is better viewed as a starting point for scenario analysis rather than a universal retirement rule.

Inflation and Purchasing Power

Inflation can significantly change retirement-income requirements.

Suppose a household spends $60,000 per year today. If prices rise over the following decades, that same lifestyle could require substantially more annual income.

This is why retirement planning should distinguish between:

• Today's dollars
• Future nominal dollars
• Expected inflation
• Investment returns
• Retirement duration

A retirement plan based entirely on today's spending without adjusting for future purchasing power can materially underestimate the amount of money required.

Taxes Can Change Your Retirement Income Requirement

The amount a household needs to spend is not necessarily the same as the amount it needs to withdraw from investment accounts.

For example, distributions from many Traditional 401(k)s and Traditional IRAs are generally included in taxable income.

Roth IRA qualified distributions generally receive different tax treatment, while taxable brokerage accounts can generate capital gains, dividends, and interest income.

This creates an important distinction between gross retirement income and net retirement spending.

Instead of simply targeting $60,000 in annual withdrawals, retirees should estimate how much gross income is required after accounting for federal and state taxes, account types, and other income sources.

Asset Allocation During Retirement

Retirement does not necessarily mean moving an entire portfolio into cash or eliminating stocks.

A portfolio may need to support withdrawals for several decades, meaning inflation and longevity risk remain important considerations.

Retirement portfolios may include combinations of:

• U.S. stocks
• International stocks
• Bond funds
• Treasury securities
• Certificates of deposit
• Money market funds
• High-yield savings
• Cash reserves

The appropriate allocation depends on factors such as retirement age, risk tolerance, spending requirements, other income sources, and the expected duration of retirement.

A portfolio that is too conservative may face greater inflation risk, while an overly aggressive allocation can expose a retiree to substantial losses during periods when withdrawals are already being made.

Sequence-of-Returns Risk

One of the most important risks during early retirement is sequence-of-returns risk.

Two investors can experience the same average investment return over a long period but have very different outcomes depending on when strong and weak market returns occur.

A major market decline shortly after retirement can be particularly challenging if the investor continues withdrawing money from a declining portfolio.

Retirees can consider maintaining an appropriate liquidity reserve and using flexible withdrawal strategies to reduce the need to sell volatile investments during severe market downturns.

How to Calculate a Retirement Savings Target

1. Estimate Annual Retirement Spending

Build a detailed budget using current expenses as a starting point.

Separate essential costs such as housing, food, insurance, and healthcare from discretionary spending such as travel and entertainment.

2. Estimate Other Retirement Income

Calculate expected Social Security, pensions, rental income, and other recurring sources.

For Social Security, review your personal benefit estimate rather than relying on a generic percentage of pre-retirement income.

3. Calculate the Portfolio Income Gap

Subtract expected recurring retirement income from projected annual spending.

For example:

$80,000 spending − $35,000 Social Security = $45,000 annual portfolio requirement

The resulting amount provides a starting point for evaluating the investment portfolio required.

4. Apply a Withdrawal-Rate Scenario

You can use the 25x rule as an initial scenario:

$45,000 × 25 = $1.125 million

Rather than treating this as a definitive target, test multiple withdrawal rates and assumptions.

5. Model Taxes and Inflation

Run scenarios using different inflation rates, investment returns, tax assumptions, healthcare expenses, and retirement durations.

A retirement calculator or financial-planning model can help illustrate how these variables affect the required portfolio.

6. Review the Plan Regularly

Retirement planning is not a one-time calculation.

Review your savings rate, investment allocation, account balances, expected Social Security benefits, insurance coverage, and retirement timeline periodically.

Major changes in income, housing, health costs, market conditions, or retirement timing may require the plan to be recalculated.

Building Retirement Savings Before Retirement

Once the target is established, the next step is determining how to close the gap.

Common retirement savings vehicles include:

• 401(k) plans with potential employer matching
• Traditional IRAs
• Roth IRAs
• Taxable brokerage accounts
• Health Savings Accounts
• Other employer-sponsored retirement plans

Automatic contributions can make retirement investing more consistent. Employees can also consider increasing their contribution rate after raises or bonuses.

The investment strategy should reflect the retirement timeline rather than relying exclusively on recent market performance.

Retirement Planning Is a Moving Target

There is no single portfolio balance that guarantees financial security throughout retirement.

A useful retirement plan connects future spending, Social Security, taxes, investment returns, inflation, healthcare costs, longevity, withdrawal rates, and account structures.

The 25x framework can provide a simple starting point, but a more complete retirement analysis should test multiple assumptions and account for the household's actual financial circumstances.

The objective is not simply to reach a particular dollar figure. It is to determine whether projected resources can reasonably support the lifestyle and expenses you expect throughout retirement.