Planning for Retirement? Figuring Out How Long You’ll Live Is Key

Planning for retirement means figuring out how much money you’ll need and how long it needs to last. A new survey shows that while many millennials expect to spend 30 or more years in retirement, most Americans struggle to estimate how long they might live.

This gap in “longevity literacy” can lead to under-saving, premature withdrawals, and financial shortfalls later in life. Understanding your potential lifespan is a key part of building a more secure retirement plan.

How Longevity Affects Your Retirement Strategy

Your life expectancy shapes how much you need to save and how long those savings must last. If you underestimate your lifespan, you could draw down your funds too quickly or retire too early. If you overestimate, you might work longer than necessary or live too frugally. Getting it right is the key to your long-term financial security.

Understanding your projected lifespan is just as important as knowing your monthly retirement expenses or ideal withdrawal rate. It also plays a key role in decisions like when to claim Social Security and how to build a sustainable drawdown plan.

What the Survey Reveals

A 2025 study found that one in four millennials expects to spend 30 or more years in retirement, but most people aren’t planning with that kind of timeline in mind.

The research, from the TIAA Institute and the Global Financial Literacy Excellence Center (GFLEC), also showed that nearly 40 percent of millennial workers expect to live to age 90 or beyond. Still, they’re not adjusting their retirement age accordingly. For every extra year of life they expect, they only plan to work one month longer.

When asked basic questions about life expectancy, many Americans were off the mark. More than one-third underestimated how long a typical 65-year-old lives, and about one in four admitted they didn’t know at all. That kind of blind spot can lead you to save less than you’ll actually need or start spending your nest egg too soon.

Why Longevity Literacy Is Often Overlooked

Many people underestimate just how long retirement can last, especially those planning to stop working before age 65. While medical advances have extended life expectancy, public understanding hasn’t kept up. Financial education often focuses on how to save and invest, but rarely teaches people how to plan for a multi-decade drawdown.

As a result, workers may overlook important factors like their personal health, family history, or gender-based longevity trends. Younger generations, in particular, miss early opportunities to harness the power of compounding or explore tools like annuities that can provide income for a long retirement.

How to Build Longevity Into Your Retirement Plan

• Use a retirement calculator to estimate, but be sure to consider factors like your age, health, and family history when making projections about your life expectancy.
• Plan for at least a 30-year retirement if you expect to stop working in your 60s.
• Consider delaying Social Security to increase guaranteed monthly income later in life.
• Follow a sustainable withdrawal strategy, like the 4% rule or a guardrails method.
• Explore lifetime income options, such as annuities, to reduce the risk of outliving your savings.
• Talk to a financial advisor about how to align your savings, investment, and income plans with a longer retirement horizon.

The Bottom Line

If you’re not planning for a long life, your retirement strategy may fall short. Longevity literacy increases your ability to realistically assess how long you might live. This can help you build a more secure, sustainable financial future.

By using better estimates and planning for a longer time horizon, you can avoid shortfalls and make smarter decisions about saving, spending, and investing in retirement.