MILWAUKEE - Only God knows your expiration date, but Northwestern Mutual Life Insurance Co. has an online calculator to give you a clue.

The Milwaukee-based insurer said it hopes people who take the quick, 13-question quiz will discover not only some ways to make life last longer, but then prepare financially for an extended run here on earth.

Northwestern Mutual highlighted its calculator this week, citing a recent report by the Centers for Disease Control and Prevention that American life expectancy continues to increase. As of 2009, the latest data available, the expected life span of women was 80.6 years and 75.7 years for men. That's up slightly from 2008.

Bob Gleeson, a Medical College of Wisconsin physician, said Northwestern Mutual's calculator is helpful because it gives participants immediate feedback on how their lifestyle and family medical history contribute to their likely longevity. The calculator starts with your current age, then adds or subtracts years from your projected final age, depending how you're faring with fundamental factors for life expectancy.

For example, the calculator takes into account whether a person is overweight, has a family history of cardiovascular trouble, eats right, exercises regularly, smokes, drinks alcohol, drives safely and visits a doctor regularly.

Rebekah Barsch, Northwestern Mutual's director of retirement markets, said as life expectancy increases, people need to plan for a lengthier retirement. That's tougher to do today than it was 40 years ago, when many Americans could count on pensions, Social Security and savings to see them through. She said people need to find a trustworthy financial professional "and start to get going on the plan."

"Planning is even more important for women for a number of reasons," Barsch said. "The reality is that women not only live longer, but are more likely to take time away from their careers to act as caregivers for their families. What this means is women have to make the most of every retirement dollar, and protecting those dollars is a top priority."