How long will you live? A reporter tries some lifespan calculators

It seemed to be as good a way as any to start researching an article on predicting lifespan. I asked Google, “How long will I live?” It offered me some calculators. The fun began.

Even before I started calculating, I had concluded I should plan for a long life. My mother is still alive at 89. My father, a lifelong, heavy smoker, made it to 84, though I wouldn’t recommend his last years to anyone. I’ve got a lot of positive risk factors: female, college education, healthy weight, exercise most days of the week, plant-heavy diet, no chronic health conditions plus good cholesterol and blood pressure numbers. (Don’t hate me. I’m a health writer. I take this stuff seriously.)

Last, I talked to Jay Olshansky on the recommendation of the American Federation for Aging research. A professor in the School of Public Health at the University of Illinois at Chicago, he helped develop an estimator that is now available to life insurance companies and will soon be used by financial services companies to help people plan for retirement.

The problem with most lifespan calculators, he said, is that they use an “additive” model. That means they start with the average expected lifespan and add or subtract years based on behaviors — which I saw as I used the Northwestern Mutual calculator that said I’d live to the unlikely 102. This doesn’t work well because behaviors or demographic factors tend to travel together, he said. “If you’re highly educated and physically active,” he said, “it’s hard to smoke.”

Normally, his calculator also uses photographs of your face, which Olshansky says is a “pretty good biomarker of risk factors” such as smoking, obesity, and sun damage. We didn’t have the photo option, so he walked me through the survey, which asked many of the same questions as the others, but weighted the answers differently. The results: My expected lifespan was 87.4 years, and I’m likely to be healthy until I’m 82.3. My alter ego, who avoided some damning questions on this calculator, made it to 82, with only about a year of disability at the end.

I was a little disappointed with my numbers after the other calculators, but Olshansky said I should think of these results as the median lifespan for 100 women just like me.

Hopefully, I won’t know whether any of the calculators were right for at least a couple decades.

Read the full article here.