Your Life Span? Ask the Calculator

EDITOR'S NOTE: This article was originally published in the March 2012 issue of Kiplinger's Retirement Report. To subscribe, click here.

Life-span predictions may sound like the stuff of tarot cards and palm readers. But an increasingly sophisticated set of online tools promise to help individuals gain a sense of how long they might live -- and retirees, health care providers and financial planners are paying attention.

Government agencies, geriatricians, financial-services firms and other groups are now offering these free Web-based calculators. The tools are gaining popularity as older adults face a host of difficult questions that revolve around life expectancy: Should you start taking Social Security at age 62 or wait and collect a bigger check at 70? Do the longer-term benefits of various types of cancer screening outweigh the immediate risks of these procedures? Given your current rate of portfolio withdrawals, do you risk outliving your nest egg?

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The most basic calculators ask for your gender and birthdate. The more complex versions ask dozens of questions about your eating habits, how you handle stress, and even how many friends you've made in the past year. Some will spit out an exact life-span estimate and offer suggestions on ways to extend it, while others will show a range of probable life spans or the risk that you'll die within, say, five years.

Yet there are a number of caveats for seniors who use these calculators to make financial planning or health care decisions. Although the results generated by these tools may appear precise, they're often based on averages for a broad population of people. "Lots of them only tell you a single number, and it's really bad to plan based on the average," says Lyle Ungar, associate professor of computer and information science at the University of Pennsylvania, who helped develop an online life-span calculator. "No calculator can be superaccurate for you."

What's more, as mortality tables and medical research evolve over time, these tools can become outdated if they're not revised. Dr. Thomas Perls, associate professor of medicine at Boston University School of Medicine and creator of the calculator at LivingTo100.com, notes that his tool once recommended vitamin E as a potentially life-prolonging supplement, but he later removed the recommendation after studies were published showing possible risks.

Making Health Care and Financial Decisions

Although patients and doctors are sometimes reluctant to discuss the issue, life expectancy can be a key factor in many health care decisions. For example, life expectancy may play into an elderly patient's decision to undergo various types of cancer screening. Older patients with a relatively short life expectancy -- say, five years or less -- might consider that potential screening benefits could take many years to materialize, whereas risks could show up right away. Those risks might include false-positive results that trigger unnecessary follow-up procedures as well as the identification and treatment of cancers that are unlikely to produce symptoms during your lifetime. A person with a long life expectancy, however, might focus on long-term benefits more than near-term risks.

"Many of the things we do in medicine impose risks immediately with delayed benefits," says Dr. Sei Lee, assistant professor of geriatrics at the University of California, San Francisco. Although colonoscopies and mammograms decrease cancer deaths, usually those benefits take five to ten years to be seen, he says.

Dr. Lee, along with several colleagues, this year launched ePrognosis.org, a site that helps health care providers get a better handle on those risk-benefit tradeoffs. The site offers 16 different calculators that estimate mortality risk over specific time periods for various groups of older adults, including those who are hospitalized, in nursing homes or living at home. Although the tools are intended for health care providers, you can use them by clicking a button stating that you're a health care professional.

The site's creators emphasize that these tools may be just the starting point for health care conversations. Yet "some patients may be surprised they may actually live a very long time and may benefit from certain procedures like cancer screening," says Dr. Eric Widera, another researcher behind ePrognosis.

LivingTo100.com, Dr. Perls's calculator, is aimed at individuals and asks dozens of questions about everything from your family's longevity to your consumption of red meat. The calculator's goal, Perls says, "is to be an educational tool and to teach people that their day-to-day health-related behaviors can have a dramatic impact not just on how long they live but how well they live."

The site provides users feedback about how their exercise habits, calcium intake, hours worked per week and other behaviors may affect life expectancy.

A retiree may scratch her head as one calculator estimates her life span at 92 and another at 103. But looking at multiple calculators can be a healthy exercise. For retirement-planning purposes, "what's good to look at is the upper bound" of life-span estimates, says Doug Carey, founder of financial-planning software firm WealthTrace. Looking at the best-case life-span scenario, after all, can help you avoid the worst-case portfolio scenario: outliving your money.

Rather than focusing on a single number, some tools offer users probabilities that they will reach a range of ages. Ungar's short calculator, available at http://gosset.wharton.upenn.edu/~foster/mortality, tells a healthy 65-year-old woman that she is expected to live to 88 years old and has a 50% chance of dying between 81 and 95.5 years old. A longer calculator available at the same site shows users how many years they might add to life expectancy by changing their behavior.

Financial-services companies offering annuities, long-term-care insurance and other products are spotting opportunity in the calculators. Northwestern Mutual's calculator (www.lifespancalc.com), for example, tells a healthy 65-year-old woman she'll live to an estimated 101 years old -- and ends with a link encouraging her to "contact a financial representative." The tool is "more educational than selling anything," says Northwestern Mutual spokeswoman Jean Towell.

For seniors deciding when to take Social Security benefits -- essentially a gamble on longevity -- the variations among life-span estimates can be particularly befuddling. Consider the healthy 65-year-old woman who earns $70,000 a year and is deciding between taking about $1,580 in monthly benefits now versus $2,420 starting at age 70. If she waits until age 70, she'll need to live roughly 9.5 years more to recoup the benefits forgone between now and age 70. Lifespancalc.com tells her she'll live to 101, Ungar's tool tells her she may live to 88, and the Social Security Administration's own bare-bones calculator at www.ssa.gov tells her she'll live to 86, based only on her gender and birthdate.

None of these tools ask her if she has cancer or a penchant for skydiving. But they'll likely lead her to hold out for higher benefits at 70 -- and despite all life's uncertainties, that's a pretty good bet.