We’ve all probably seen those commercials that ask us, “What’s your number?” They mean, of course, how much money will you need to save before you can retire. There are several ways to answer that question (we prefer to consider the question, “How much retirement income can you generate?), but I often get another question when I talk with people about retirement: “How long will my money last?”

The answer depends on your lifestyle and longevity. Stated another way, “How long will your retirement last?” Retirement is sometimes described as a really long unpaid vacation. Although we usually know how long a two-week vacation is going to last, predicting the length of retirement is not so obvious.

How Long Do I Have, Doc?

Fortunately, there are some tools to help us figure that out. Just as knowing how many vacation days we have helps us budget for that next trip, so too does a better understanding of our own longevity help with retirement and related plans. As you have probably heard, Americans as a group are living longer than they did 40 years ago. That means more retirement time in general, but what does it mean for us individually?

According to the Society of Actuaries (SOA), among people in their middle fifties, 1 in 2 women and 1 in 3 men can expect to celebrate a 90th birthday. In addition to considering how long your grandparents and parents lived, you can also use modern technology to zero in on your own life expectancy. Here are two calculators that make this task easier than you might think:

  • SOA Longevity Illustrator – Answer just four questions (age, gender, smoking, general health) to see your probabilities for living to various ages.
  • Living to 100 – This calculator asks quite a few more detailed health and lifestyle questions, and it helps if you’ve been to the doctor recently and have a fresh copy of your cholesterol numbers and blood pressure readings handy.

Running My Own Numbers

It just so happens I recently had a medical checkup, so I ran both calculators for myself to see what they had to say regarding my fate. I was surprised (somewhat disturbingly) to see that Livingto100.com projected my life expectancy all the way out to 95 years! I’m healthy, but certainly no athlete (hello, dad bod), and there is some history of heart disease among my family members (but not me – not yet). I also don’t smoke, which is a huge health asset in addition to saving me a bundle of cash.

The SOA’s longevity illustrator provides a more general result, showing the probability of living a specified number of additional years from today. Due to the limited number of variables – it only asked 4 questions – I expected the outcome to be a bit more pessimistic, and I was right. Even if I assumed the option for “excellent” health, the longevity illustrator gave me a better than average chance of seeing age 85 (66%), a less than average probability of celebrating age 90 (44%) and a gloomier 1-in-4 chance of reaching age 95 (25%).

Why the Odds Matter

Taken together, one calculator tells me a long life out to age 95 is possible (www.livingto100.com), and the other calculator (www.longevityillustrator.org) tells me the likelihood I’ll reach that 95th birthday, along with probabilities for all the other ages along the way. As a rather old English saying reminds us, “There are three kinds of falsehoods: lies, damned lies, and statistics.”

How I’m Planning for a Longer Retirement

While no calculator or crystal ball can tell me exactly how long I may be around, these probabilities do give me a track to run on so I know what my trade-offs are as I make various financial decisions. For example, given the possibility and significant probability I may be facing a very long retirement, I’ve decided my retirement goals include the following:

  • Contribute to my 401(k) plan at work to the maximum annual IRS limit.
  • Work as long as I enjoy what I’m doing and physically can; I likely will need those additional years of 401(k) contributions.
  • Delay Social Security to age 70 and maximize this payment.
  • Pay off all my debts – including our mortgage – before I retire.
  • Consider converting some of my retirement nest egg to an income annuity as an additional guaranteed lifetime income supplement to my Social Security to make sure basic living expenses are more or less met no matter what.
  • Consider a reverse mortgage line of credit as a financial lifeboat if long-term care or other unexpected and severe expenses begin to prematurely drain my retirement savings.

When the Numbers Show a Shorter Retirement

Of course, if my projections were not so long-lived, I would focus on spending more early on, not working quite so long, cashing in Social Security a few years sooner, and not worrying too much about buying an annuity. These are highly personal choices, and your priorities are likely not the same as someone else, which makes this a good conversation to have with a financial planner.

If you want to keep your retirement goals really simple: save, pay off debt, and invest as if you will be that 90-something with a four-alarm flaming birthday cake. Your future self will thank you if you live that long and if not, your heirs and/or a beloved charity will thank you for the generous financial legacy you leave behind.

However, if your planning efforts demand more precision, use the calculators to dial in your own probabilities. Keep in mind, no calculator is perfect, and medical science is improving all the time. You might want to keep a little something in reserve so you can still enjoy that 90-somethingth birthday celebration.