The oldest members of the baby boom generation are turning 65 this year, but many are woefully unprepared financially to stop working. The "nest-egg" is a myth, says Susan Jacoby in the Los Angeles Times, noting that nearly half of older Americans have no income from stocks and savings accounts. And, even those wealthy enough to have some sort of nest egg have far too little in it, according to Federal Reserve data analyzed by The Wall Street Journal and Boston College's Center for Retirement Research. Here, a brief guide, by the numbers, to the "nest-egg myth."

Age the oldest baby boomers are turning this year

More than 8.5 million
Projected number of Americans who will be over age 85 in 20 years

Less than 25 percent
Amount the median household headed by someone aged 60 to 62 has of the retirement savings needed to maintain his or her standard of living, according to data from the Federal Reserve. "Inevitably, we find that, for the average person, there is not enough there," says financial adviser Paul Merritt. "The discussion turns out to be: What kind of part-time work do you want to do after you retire?"

About 50 percent
Amount of wealth lost by baby boomer households between 2004 and 2009, due to shrinking 401(k) accounts and the real estate collapse

Only 50 percent
Share of working Americans that have tax-sheltered retirement accounts

75 percent
Number of Americans over 65 whose annual income (including Social Security) is less than $34,000, according to a report from the Congressional Research Service. "Furthermore, household income drops precipitously with every decade, and most of the poor in their 80s and 90s are women, who — unless their husbands possessed vast wealth — are very likely to become poorer when they are widowed."

85 percent
Assumed share of a household's pre-retirement income needed to maintain the same standard of living in retirement

Median income, in 2009, for households nearing retirements (with heads aged 60 to 62) that have 401(k)-type accounts

The 85 percent of that salary needed for requirement

As much as $35,080 a year
Amount Social Security will provide for such a household

Amount needed from other sources to maintain pre-retirement standard of living. "Most 401(k) accounts don't come close to making up that gap,"says E.S. Browning in The Wall Street Journal.

Amount the median 401(k) plan holds, according to the Center for Retirement Research

Amount per year such an account would provide a household, less than 25 percent of the $36,465 needed

9 percent
The current median amount that people contribute to 401(k) plans, including employer contributions, according to Vanguard Group, a leading provider of the plans. "In general, people facing problems today got too little advice, or bad advice," says Browning. "They didn't realize that a 6 percent annual contribution, with a 3 percent company match, might not be enough."

12 to 15 percent
Amount, including employer contribution, that Vanguard recommends people contribute to their 401(k) plan

Sources: Los Angeles Times, Wall Street Journal