The number of homemakers who have lost their main source of income, primarily through widowhood or divorce, and need financial assistance is growing rapidly, and already has reached 11.5 million women, according to a study released yesterday by a nonprofit public interest group.

The study, by the Displaced Homemakers Network, is based on an analysis of 1980 Census data, and suggests that there may be three times as many displaced homemakers as reported in a 1976 study by the U.S. Department of Labor.

"These are the women who drove the car pools, ran the bake sales and organized the Scout troups and the baseball leagues," said network executive director Jill Miller. "And for their very sizable contributions to their families, our communities and our country, they have gotten a very raw deal."

Former network president Georgetta Mitchell said that despite the political and economic gains that women have made in recent years, a "sizable percentage of American women are still only a man away from poverty," so that when they lose their husbands they also lose their incomes.

Displaced homemakers, said network President Donna LeClair, are struggling to "make ends meet without unemployment insurance, without health insurance in many cases, and without jobs. These women are paying a very high price for their unpaid careers as homemakers."

At least two-thirds of displaced homemakers are white widows over age 55 and a majority are unemployed and poor and lack a high school diploma, the study found.

But, Miller said, "all kinds of women can be displaced," including welfare mothers, country club matrons and battered women. She said that displaced homemakers "are black, white, hispanic, Asian and native American women from rural and urban areas," some of whom have small children to support.

The study, "A Status Report on Displaced Homemakers and Single Parents in the U.S.," provides a breakdown by states. In the Washington area, the District has 50,213 displaced homemakers; Maryland, 188,792, and Virginia, 217,370.

The stories of displaced homemakers, Miller said, "go something like this: They are unemployed because they have no recent job history, training or education. They are frequently too young for Social Security and many will never qualify because they have been divorced from the family's wage-earner."

Network officials said that their study documents a need for better and more readily available employment services for displaced homemakers.

"Now that the magnitude of the problem is clear, we must allow no further excuses for inaction," LeClair said. She said that all legislation that addresses job training, vocational education, child care, literacy, transportation assistance and welfare reform should consider the special needs of displaced homemakers.

Maryland has one of the strongest and oldest efforts for displaced homemakers, network officials said. Maryland has 24 displaced homemaker programs in Rockville, Bowie, Capitol Heights, Columbia, Largo, Annapolis, Baltimore and other cities.

Virginia has 24 programs, including those located in Annandale, Arlington, Alexandria, Falls Church and Vienna, the network said, and the District has one program, which focuses on younger women.

The network study defined the displaced homemaker as a woman whose principal job has been homemaking and who has lost her main source of income because of divorce, separation, widowhood, disability or long-term unemployment of a spouse or loss of eligibility for public assistance.

Applying that definition to U.S. Census data for 1980, the network concluded that there are at least 11.5 million displaced homemakers. But the actual number likely exceeds that number, network officials said, because it is difficult to identify from Census reports the displaced homemakers whose spouses are disabled, single parents who will lose assistance when their youngest child reaches 18 and farm wives whose farms are heading for foreclosure.