Most Americans need a major reality check when it comes to their retirement.

A survey of U.S. workers shows most haven't saved nearly enough money to retire comfortably, and many don't have any idea how much they'll really need.

Three-quarters of the polled workers have saved less than $100,000, yet 65 percent feel very or somewhat confident that their nest egg is large enough, say experts at the Employee Benefit Research Institute, which conducts the annual Retirement Confidence Survey with Mathew Greenwald & Associates, Inc.

The 2005 results show workers are underestimating how much money they'll need, and overestimating how long they'll be able to work, researchers said. Only 42 percent have figured out how much they should save for retirement – and of that group, 10 percent said they guessed.

Some just don't want to know. ''I don't want to see how far off I am. It's intentional,'' Joel Press, a 35-year-old lawyer with DC Comics in Manhattan told Newsday.

Workers are not saving enough for retirement for three main reasons, the survey found: The cost of paying everyday expenses (49 percent), child-rearing expenses (39 percent) and medical costs (35 percent).

“Eliminating consumer debt and curbing spending is a must if many workers are to save adequately for a comfortable retirement,” Mathew Greenwald, president of Greenwald & Associates, said in a statement. “Six in 10 workers report their level of debt is a problem, and half report they carry credit card debt."

The survey also revealed the factors that would make workers more likely to contribute to a 401(k) retirement plan at their workplace – matching money from their employers.

According to 72 percent of those who did not contribute to an employer retirement plan, a matching contribution of up to 5 percent of their salary would make them much more likely or somewhat more likely to participate.

Eighty-two percent of eligible workers said they signed up for their employer's retirement savings plan. About two-thirds (66 percent) of noncontributing workers said automatic enrollment in a retirement plan upon being hired would make them very likely or somewhat likely to participate.

The survey, first conducted in 1991, tracks the attitudes and behaviors of American workers toward saving, retirement and long-range financial planning. This year's survey, which polled 1,253 workers age 25 and older, found that 68 percent are doubtful that Social Security will offer the same benefits retirees receive today when they retire. This skepticism has remained constant in recent years.

Full results can be found at www.ebri.org and at www.choosetosave.org.