Why Most People Underestimate Their Retirement Number

The 70% Income Rule Is Quietly Misleading People

For decades, financial planning rule-of-thumb said you need roughly 70% of your pre-retirement income each year to live well in retirement. That figure made sense in an era when retirees paid off their mortgages early, stopped commuting, and had fewer healthcare costs. Today, none of those assumptions hold reliably.

Healthcare alone changes the picture dramatically. A 65-year-old couple retiring in 2024 can expect to spend roughly $315,000 out-of-pocket on healthcare over the course of retirement, according to Fidelity's annual estimate. That cost is not captured in a simple income-replacement percentage. If you budget for 70% of your salary and then face a serious illness, the shortfall is not a rounding error.

What Inflation Does to a Fixed Savings Target Over 25 Years

Say you retire at 65 with $800,000 saved and plan to withdraw $40,000 per year. At 3% annual inflation, that $40,000 needs to be $48,500 by year ten just to buy the same things. By year twenty, you need nearly $70,000 to maintain the same purchasing power. A flat withdrawal strategy does not survive this. Try the retirement savings calculator to see your own numbers.

This is why the savings target itself is less important than the withdrawal rate. The widely cited 4% rule, based on research by financial planner William Bengen in 1994, says you can withdraw 4% of your portfolio in year one and adjust for inflation each year without running out of money over a 30-year retirement. But that study was modeled on historical U.S. market returns. In a lower-return environment, many researchers now suggest 3% to 3.5% is safer. The practical difference is large: a 3.5% withdrawal rate means you need roughly $1.14 million to pull $40,000 annually, not $1 million.

Running the Real Numbers With Your Own Salary and Timeline

The fastest way to stop guessing is to plug your actual numbers into a retirement savings calculator. You input your current age, planned retirement age, existing savings, monthly contributions, and an expected annual return. The output shows how much you will accumulate at retirement, and whether that balance funds your target income for however many years you expect to live.

Small changes to these inputs produce very different outcomes. Adding just $200 per month to contributions at age 40 instead of age 50 can add roughly $85,000 to a portfolio by age 65, assuming a 7% annual return. That is not a minor adjustment; for many people, that difference determines whether they retire on schedule or work an extra three years.

One scenario worth testing: what happens if you retire at 63 instead of 65 and Social Security is not claimed until 67? You draw down savings faster in those early years while also missing two years of contributions. Many people do not model this gap, and it is one of the most common ways a retirement plan quietly breaks down.

The Social Security Offset People Forget to Account For

Social Security is not a bonus on top of your savings plan. It should be a core input in your retirement math, and the timing of when you claim it changes the total benefit significantly. Claiming at 62 reduces your monthly benefit by up to 30% compared to waiting until your full retirement age. Waiting until 70 increases it by 8% per year past full retirement age.

If your full retirement age benefit is $2,000 per month, claiming at 70 gives you $2,480 per month instead. Over a 20-year retirement, that gap compounds to roughly $115,000 in additional lifetime income, before cost-of-living adjustments. The right move depends on your health, your spouse's situation, and how much you have saved elsewhere, but most people never run this comparison at all.