President Carter will spell out a multibillion dollar federal and military pay raise either today or Thursday. He is considering three options for the pay package that will benefit 360,000 U.S. white collar workers and military personnel in metro Washington. All of the choices before him are based on his proposal to limit the average increase in October to no more than 5.5 percent.

The options:

I - Give everybody the same 5.5 percent pay raise. That would go to white collar civil servants (except for some top-paid career and political executives) and to military personnel and be effective in October. Postal workers, blue-collar federal employes and government retirees will not be included in the raise.

2 - Stagger the percentage amounts of the Oct. 1 increase. High grade and middle level employes would get the biggest percentage increases. Lower level workers, whom the government says already are paid as much or more than their private industry counterparts, would get less than 5.5 percent. The total cost of this option would be the same as an across-the-board increase and maintain the "average" at the magic 5.5 percent figure.

3 - Delay the raises until January 1979 or later. Idea here would be to give workers larger percentage increases but hold the total cost for the pay boosts at the 5.5 percent level for the remainder of the fiscal year which begins in October.

Insiders say option three is not very likely, but the President is studying it. It has the advantage of allowing him to give restive government workers bigger increases while permitting him to tell the nation that he kept the raises within his previously established 5.5 percent guidelines.

Whatever the President decides should be it. Congress does have the option of rejecting the President's proposals and substituting a catchup with-industry raise of around 8.4 percent. Congress is not about to act on its own to raise federal salaries, especially since Congress will not benefit this year just before an election.

The President will call the shots on federal pay this year, and you should be hearing those shots very soon.