Four out of five Washington area residents feel that oil company profits are excessive, according to a Washington Post poll. They felt that way even before President Carter announced his plan to decontrol oil prices and thereby possibly allow oil companies to make far greater profits than they do now.

Those polled by the Post were evenly split on whether there actually is an energy shortage in the United States.

But whether they believe there is a shortage or not, two out of every three people interviewed said they feel the oil companies are taking advantage of cirucmstances to drive up oil prices.

These findings were gleaned in interviews with 934 area residents Tuesday through Friday night, with only a small percentage occuring after Carter's televised energy message Thursday evening.

In that message, the president called for a "windfall profits" tax to cut into what he called some of the "unearned" profits the oil companies would receive as a result of decontrols. That tax request has since been sharply criticized by spokesmen for the oil firms, and some leaders on Capitol Hill say Congress will not enact it.

The president's message came too late for Post interviewers to ask direct reaction to it, but the overwhelming local sentiment that profits already are excessive and other findings in the poll suggest that there would be near unanimous support for a tax on windfall profits.

Many area residents would do more than tax the oil firms, in fact. Asked whether "most Americans would be better off or not better off if the government broke up the major oil companies," a plurality of 47 percent said most people would be better off if they were broken up. Thirty-five percent disagreed. The other 18 percent said they were not sure.

While opinion is divided about the extent of an energy shortage today, the majority feels that one is coming. Those interviewed were asked to "picture a scale from zero to 10, with zero meaning there is no real energy shortage and 10 meaning there is a severe energy shortage."

They were then asked to state at what point on the scale the country stands now, where it will stand in a few months, and where it will stand in five years. Forming all their responses into averages, those interviewed see the nation at 4.8 on the energy shortage scale now, at 5.5 in a few months, and at 6.4 in five years-clearly moving toward a worsening energy situation.

A similar question was asked about future energy shortages in another way. "Do you believe Jimmy Carter or not when he says there will be an oil shortage in the 1980s?" respondents were asked. Three in every five said they did believe him, 29 percent said they did not and 10 percent said they were not sure.

Those who believed Carter were not necessarily Carter supporters. Fifty-three percent of those who described themselves as critics of Jimmy Carter said they believed him when he spoke of a coming oil shortage.

In fact, the factors that often divide the public, such as political partisanship, conflicting ideologies, differing incomes and educational backgrounds, do not seem to divide Washington area residents deeply on energy questions.

There are some gross differences. Republicans as a group would not break up the oil companies while Democrats and independents would. Poor people are much more likely than the more affluent to consider the energy shortage a hoax perpetrated by oil companies.

But by and large, in views on the energy problem, the blocs that often are in conflict find themselves differing only in degree, no t kind, and then only slightly.

Seventy-four percent of college graduates, for example, believe oil firm profits are excessive, while 82 percent of those who did not complete high school take that view. Similarly, 89 per cent of those who call themselves liberal say those profits are excessive, along with 71 percent among those who call themselves conservative.

Compared to the way they split on many political matters, those are small differences.