Eighteen dollars and forty-six cents. Before deductions.

That is the weekly amount the average white-collar government worker will get this fall if Congress, as expected, goes along with the 5.5 percent federal-military pay raise President Carter recommended yesterday.

Congress now has 30 days to do what it often does best - nothing - to make the raise official. Either the Senate or the House could overturn that toned-down 5.5 percent raise, and instead vote an 8.4 percent increas. The latter figure, government statisticlans say, is the amount needed to bring most government job pay levels up to par with industry.

Congress could overrule the president on this one. It could demand higher pay rises for federal workers. For that matter, all 535 members could also leap from the Washington Monument. Odds on either one happening are about the same.

The pay raise is due in October. Politicians, already suffering nervous tics from taxpayer revolts, must face those voters in November. Many incumbents hope to ride the wave of anti-Washington sentiment back to Washington. They won't do it by voiting a higher pay raise for government employes.

The voters are unhappy with big government, ineffective government, costly government. Right or wrong, these sentiments are strong everywhere. In California, the taxpayers revolted and made an overnight convert to economy of Gov. Jerry Brown. He is not alone.

Today's headlines and lead stories on television won't make it any easier for government unions to pry more money out of Congress.

People hear and read about postal workers threatening an illegal strike - cutting off 44 million federal checks sent through the mail each month - although they got a 19.5 percent wage offer and a promise of a no layoffs during a 3-year contract. The working conditions that many workers are protesting, and the higher wage settlements in industry, don't come across as strongly.

We are told that the continuing, and growing, scandals in the General Services Administration may replace Teapot Dome in the history books. The White House has said that the civil service is unmanagable and must be reformed.

Stories about student loan defaulters working for HEW, and government workers illegally drawing welfare don't help. It seems to be a fact that the "average citizen cusses the mail service while praising his or her individual letter carrier.

People have friends and relatives working long, hard hours in government, but remain convinced that government in general is full of overpaid drones who enjoy job security and eventual pensions beyond the reach of the average nonfederal worker.

Federal union leaders will fight the good flight, trying to get a full 8.4 percent catchup raise with industry. But some would agree privately that, given the times, 5.5 percent is a pretty good deal.

"Though not unexpected," says Virginia Connery of the National Treasury Employes Union, "the president's action is but one more signal that political expediency rather than fairness and equity, is the guiding force behind the wage-setting and personnel policies of this Administration."

Connery's frustration and views will be shared by many people in Washington, and in big federal employment centers. But the feds, despite their numbers, remain a minority group and one that is not very popular at the moment.

Congress may make noises about overturning the president's pay plan, but it will mostly be to soothe government constituents and unions. The lid, it appears, is firmly screwed on for this year.