Retirement savings: Why $1M may not be enough

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401(K) 2012

(CBS News) One million dollars in retirement savings sounds like a lot, but financial experts warn that even a seven-figure nest egg may not be enough for the average couple.

So how much is enough -- and how can you get it?

For bare-minimum saving, CBS News contributor and analyst Mellody Hobson recommends the average person needs 70 to 80 percent of their annual income for each post-retirement year.

But putting that into practice doesn't appear to be happening for many Americans, with a new study by the Employee Benefit Research Institute revealing only two-thirds of Americans have saved anything -- and the average American has saved less than $25,000 for retirement.

To make your money work for you, Hobson suggests getting "really aggressive and save now."

"Even small amounts make a difference," she said.

Though many people plan to rely on Social Security payments, Hobson warns it's there "for now," and noted the average Social Security check in the U.S. is $1,230 a month -- less than $15,000 a year. She said, "(That's) not a lavish lifestyle. And most people, 70 percent of their income will be Social Security."

Holding off on retiring for as long as possible is a good idea, according to Hobson. She explained, "The full retirement benefit comes to most people at the age of 66. That's where you get 100 percent of your Social Security. For every year you wait, you get eight percent more up to the age of 70. So the difference of what you get at 66 and 70 is huge."

For more with Hobson, watch her full interview above.