President-elect Reagan is expected to support both of the federal pay raise recommendations President Carter is leaving with Congress in his final budget.

The biggest item is a scaled-down 5.5 percent pay raise this October for Uncle Sam's 1 million white-collar workers, including 300,000 people in this area. The second is for a catch-up pay raise averaging around 17 percent for elected and appointed officials, and 15 percent for about half of the federal Senior Executive Service.

Carter's original budet called for a raise in excess of 2 percent for white-collar feds -- scientists, secretaries, supervisors and the like -- and increases of up to 40 percent for federal judges. But both figures were modified in the final version that goes to Congress later this month.

Most Reagan aides favor the executive raises, which will benefit those frozen at $50,000, to aid them in recruiting the kind of top-drawer, successful types Reagan says he wants to help him manage government. Their only regret with the white-collar federal pay proposal is that Carter didn't come in with a higher figure so they could have reaped the political benefits of cutting it.

Reagan will not lmake his firm and final recommendation for a white-collar federal pay raise until August. Obviously a lot can happen between now and then. But an educated guess is that he will NOT propose anything higher than the 5.5 percent Carter has suggested and, very probably, will recommend a lesser increase. Congress isn't likely to override him and demand more money for bureaucrats.

Final action on the executive pay raise will come sooner. If the proposal goes through established machinery, Congress will have 60 days after the budget is submitted to approve or reject the executive-legistlative-judicial salary raises. Both the Senate and the House must take record votes on the pay issue, if current rules are obseraved. It is also possible that somebody will introduce legislation to raise salaries by that amount, and that bill could be attached to another piece of legislation as a "rider." The other possibility is that Congress does nothing on the pay issue. The existing pay "cap" on federal salaries is due to expire automatically this June, unless Congress reimposes it in new legislation or by adding it to appropriations bills.

Most of the people who would benefit from an executive pay raise live and work in the metro Washington area. They are the nearly 8,000 career and political members of the Senior Executive Service. If the pay raises go into effect, or the "cap" on SES salaries expires in June, this is what the new SES pay levels would look like:

SES Level 1, $52, 247; Level 2, $53,996; Level 3, $55,804; Level 4, $57,673; Level 5, $59,604 and Level 6, $61,600. Most SES people are at Level 4 now. All of the pay levels now are subject to the same $50,112.50 ceiling.