A new survey by pollster Louis Harris says that 51 percent of Americans are willing to pay an additional $25 a year in their federal taxes to support arts programs.

The survey, released yesterday by the American Council for the Arts, indicates that Americans have become more active in the art, both as spectators and as participants.

The poll, sponsored by Philip Morris Inc. and the American Council for the Arts, with a grant from the National Endowment for the Arts, surveyed a cross section of 1,501 adults of both sexes by phone last July. Harris conducted similar surveys in 1973 and 1975.

The new poll shows that the amount of leisure time has apparently decreased -- down from a median of 24.3 hours a week in 1975 to 19.2 hours this year. But 64 percent of those surveyed this year agreed with the statement, "If there were more theater and concert events in this community, I would attend more frequently." In the 1975 poll, only 54 percent agreed with that statement.

Harris found that 81 percent of respondents believe it is important to have "more and better arts and cultural facilities for both the performing and visual arts."

According to the survey, 22 percent of the sample went to live theater performance two or three times in the last year. In the 1975 survey, that number was 15 percent. In 1980, 20 percent went to live popular music performances two or three times in the last year -- up from 14 percent in 1975.

Fifty-nine percent of the respondents disagreed with the statement that "the arts can only be enjoyed by a privileged few who have the financial means to attend arts events." Thirty-nine percent agreed. In 1975, 48 percent disagreed and 46 percent agreed.

Harris found a dramatic increase in personal involvement in the arts. For instance, 44 percent of the surveyed group said that they engage in photography -- an increase from 19 percent in 1975. And the number of people who said they play musical instruments rose from 18 percent in 1975 to 30 percent in 1980. Those involved in either ballet or modern dance have risen from 9 percent in 1975 to 20 percent in 1980; and those who sing in a choir or choral group have risen from 11 percent in 1975 to 21 percent in 1980. The number of creative writer rose from 13 percent in 1975 to 22 percent this year.

"I'm delighted and surprised," said Robert Carter, team leader for the Reagan transition committee on the National Endownment for the Arts, when informed of the results. Carter has not yet read the survey itself.

Of the apparent willingness of a majority of people to pay $25 each in federal taxes for the arts, Carter said, "I think that's a wonderful statistic. I think it's great if it's true."

He said that a $25 per-capita federal tax allocation for the arts "would have a tough time flying in Congress." (The present per-capita allocation is approximately 70 cents, according to the Harris survey.)

But a voluntary check-off box on income-tax forms might be a good idea, Carter said. "The check-off box has raised a lot of money for the Federal Elections Commission -- more than they know how to spend."

Asked who should provide assistance to arts organizations if aid is necessary, the Harris respondents selected: individuals, 84 percent; foundations, 79 percent; business and corporations, 72 percent; state government, 60 percent; and the federal government, 50 percent.