How Much Do You Need to Retire? Calculating Your Savings Target

The Number That Changes Everything

Surveys consistently show that most Americans don't know how much they need to save for retirement — and those who guess tend to significantly underestimate. A 2023 EBRI survey found that only 48% of workers had ever tried to calculate a retirement savings target, yet the exercise takes under an hour and produces a number that should anchor every savings decision for decades. Arriving at a credible retirement target isn't about predicting the future precisely; it's about building a framework that holds under a range of realistic scenarios.

The Four Key Inputs

Any retirement savings calculation requires four foundational estimates:

1. Annual expenses in retirement — Not your current income, but what you expect to spend annually once you stop working. Many retirees spend 70–85% of pre-retirement income, but actual expenses vary widely by lifestyle, healthcare needs, and housing status.
2. Non-portfolio income sources — Social Security, pensions, rental income, part-time work. These reduce how much your portfolio must provide.
3. Retirement duration — Life expectancy is the largest unknown. The SSA's actuarial tables show a 65-year-old woman has a 50% chance of living to 87; a couple both age 65 has a 50% chance that at least one survives to 92.
4. Sustainable withdrawal rate — The percentage of the portfolio drawn annually; this determines the portfolio size needed to support a given income for a given duration.

The 4% Rule

The 4% rule originated from William Bengen's 1994 landmark paper in the Journal of Financial Planning. Bengen analyzed historical stock and bond return sequences and found that a portfolio allocated 50–75% to stocks could support annual withdrawals of 4% of the initial portfolio value (adjusted for inflation each year) for 30 years or longer without exhaustion in every historical scenario tested.

The inverse of the 4% rule provides a simple savings target formula:

Required Portfolio = Annual Portfolio Income Needed ÷ 0.04

Example: If a retiree needs $80,000/year from investments (after Social Security and other income), the target portfolio is $80,000 ÷ 0.04 = $2,000,000.

The 4% Rule's Limitations

• Based on U.S. historical data; future returns may differ given current valuations.
• Assumes a 30-year retirement — a 40-year retirement requires a lower withdrawal rate, approximately 3.3–3.5%.
• Does not account for variable spending; many retirees spend more in early retirement and less in later years (the retirement spending smile).
• Assumes no adjustment based on portfolio performance; flexible spending rules outperform rigid withdrawal strategies in simulations.

Age-Based Savings Benchmarks

Fidelity's benchmarks assume Social Security provides approximately 45% of pre-retirement income (consistent with the SSA's average replacement rate at full retirement age), a 15% savings rate throughout the career, and retirement at 67 with a 45% stock / 45% bond / 10% short-term investment mix.

Healthcare Costs: The Overlooked Variable

Fidelity estimates that a 65-year-old couple retiring in 2023 needed approximately $315,000 in after-tax savings to cover healthcare expenses throughout retirement, even with Medicare coverage. This does not include long-term care costs. According to Genworth Financial's 2023 Cost of Care Survey, the national median annual cost of a private nursing home room was $108,405, and assisted living cost $64,200. Without long-term care insurance or dedicated savings, these expenses can rapidly deplete retirement portfolios.

Monte Carlo Simulation

Modern retirement planning tools use Monte Carlo simulation to estimate retirement success probability across thousands of randomized return sequences. Rather than using a single average return assumption, Monte Carlo incorporates return volatility and sequence-of-returns risk — the danger that poor returns early in retirement permanently impair the portfolio.

The Savings Rate Required

The savings rate needed to hit a 10× salary target at 67 starting from zero at various ages (assuming 7% average annual nominal return):

• Starting at age 25: approximately 12–15% of income per year
• Starting at age 35: approximately 20–25% of income per year
• Starting at age 45: approximately 35–40% of income per year
• Starting at age 55: mathematically difficult without very high income or inheritance

These figures include combined employee and employer contributions to all retirement accounts. The power of compounding makes the starting age far more impactful than the specific savings rate chosen later in life.

This article is for informational purposes only and does not constitute financial advice.