Washington ? What is the difference between a high school diploma and a medical degree? About $3.2 million, says the Census Bureau.

Someone whose education does not go beyond high school and who works full time can expect to earn about $1.2 million between ages 25 and 64 a typical work-life period, according to demographers.

Graduating from college and earning advanced degrees translate into much higher lifetime earnings: an estimated $4.4 million for doctors, lawyers and others with professional degrees; $2.5 million for those with a master’s degree; and $2.1 million for college graduates.

The findings come from an agency survey being released today that charts the influence of education on lifetime earnings.

Not all students look at college as an investment, “but I’m sure parents do,” said Jacqueline King, policy analyst with the American Council on Education, a higher education advocacy group. “The challenge is to convince those high school students on the margins is that it is really worth their time to go to college.”

Kevin Malecek, a graduate student in American politics at American University in Washington, acknowledged the time commitment was significant.

“But most people do find it worth it. They go to every single class, and they are trying to get the most out of their own dollar,” he said.

The survey was conducted between March 1998 and March 2000. All estimates are based on 1999 salaries and probably will increase as salaries rise over time, Census Bureau analyst Jennifer Day said.

The estimates do not account for inflation or for differences in the earnings potential of the various fields of study and degree majors. For instance, people with computer science degrees tend to earn more than those with social work degrees.

“It’s pretty integral right now that you have a bachelor’s degree,” said Kaydee Bridges, a senior studying international relations at Georgetown University. “And I imagine that when you have children … you have to have a master’s degree to get anywhere.”

Disparities remained between men and women, especially among older workers with higher degrees. Men with professional degrees may expect to earn almost $2 million more than women with the same level of education.

More men hold better-paying executive positions in corporations, hospitals and law firms, Day said. The difference also takes into account that more women than men leave work to care for a child and that women often do not return to their job full time.

Americans overall continue to stay in school longer. In 2000, 84 percent of adults 25 and older had at least a high school degree, and 26 percent had a bachelor’s degree of more, both records.

The survey was conducted separately from the 2000 census. The last time the bureau released such figures was 1992, though the estimates are not directly comparable because they have not been adjusted for inflation in 1999.

In 1992, a high school graduate could expect to make $820,870 at work between 25 and 64. College graduates could make $1.4 million, while professional degree-holders more than $3 million.