President Carter this week will tell you what kind of a pay raise you will be getting this October. The boost will go to one million white collar civil servants, including 300,000 here.

The raise will show up in paychecks for mid-October or early November. If you know the amount, you know more than the president.

Carter aides say he is still studying his options. The betting is the boost he will okay will be 9.1 percent. But nobody is betting much.

Under current law, Carter has almost total freedom to pick any number he wants. The law says only that U.S. workers should get "comparability" with industry. Nobody says what comparability is, or how it can be genuinely arrived at.

Preliminary data given the president by his pay agents indicate a raise of 13.49 percent is justified if federal workers are to keep up with industry counterparts.

Opponents of that figure say the government salary measurement system is meaningless because it does not include the value of fringe benefits, it excludes wages paid by state and local government workers.

Under a broader system that took those factors into account, the president said in January that federal workers deserved a 6.2 percent boost. That figure has been upgraded to 7.8 percent in budget estimates.

U.S. unions say the 13.49 percent figure is the absolute minimum that Carter can grant them and hope to retain the good will, and November votes, of his giant office staff, the federal bureaucracy.

Unless Carter submits an alternate figure this week, the full catchup-with-industry raise would go into effect automatically.He is, however, expected to submit an alternate pay raise proposal, either the 7.8 percent, or 9.1 percent, or something in that ballpark.

Technically Congress has 30 days to veto the alternate pay proposal from the president, and force a higher raise. In fact, that isn't in the cards. With economy, inflation and "waste in government" political issues, few members of Congress would push for a raise higher than the president proposed. The exceptions will be Washington-area legislators -- and a handful of senators not up for reelection this year -- who represent districts that have lots of federal workers.

Here are the numbers the president will be choosing from:

The 13.49-percent raise needed for a full-catchup with industry. Don't mortgage your house in anticipation of that kind of raise.

The 6.2-percent figure Carter originally budgeted in January. Lots has happened since then, both statistically and politically. Inflation has gone up, industry salaries have gone up and Carter is looking for all the votes he can get. Giving federal workers that "small" a raise probably wouldn't boost Carter's public stock, but it would hurt him with federal workers. A real long shot.

The 7.8-percent figure. The Administration is touting this one. It may be a teaser. Again the feeling is Carter will have to go higher if he is to win back bureaucrats ticked off by paid parking, hot water cutoffs and assorted other grievances.

The 9.1-percent figure. This is the odds-on favorite. The President of the American Federation of Government Employes has predicted Carter will go with that amount, although the AFGE leadership says it isn't enough. Still, it might be enough to save Carter from attacks by conservatives while winning the hearts of some government workers.

National Federation of Federal Employes union president James Peirce says he has heard the same 9.1 percent message and doesn't like it.

Peirce says federal wokers deserve more than that, and his people -- who meet in convention in mid-September -- won't be happy with a point less than 13.49 percent.

National Association of Retired Federal Employees reports its membership has gone over the 400,000 mark.That is a jump of nearly 150,000 in the past two years.

NARFE recruiting has been helped by the bad news coming out of Washington: Proposals to merge the federal retirement system with social security: the plan to eliminate one of the two annual cost-of-living raises and talk that Congress next year will seek to hold U.S. retirees to 75 percent of the annual inflation rate.