The Reagan administration is shopping for a new yardstick Uncle Sam can use to see if he is paying his million-plus white-collar workers too much, not enough or just the right amount to keep them at par with the private sector.

Many federal workers are convinced that their salaries are much smaller than those they would get if they were working for industry. Many people in industry see it just the reverse.

The administration thinks that much of the paycheck discontent stems from the fact that the government tells workers they should be getting much bigger raises than it gives them. For example, last year the government's pay data indicated that civil servants were due a raise of nearly 20 percent. Reagan said the survey results did not mirror the reality of the marketplace, and gave them a 4 percent raise.

Presidents Nixon, Ford and Carter also felt the government's so-called "comparability" pay system produced proposed pay raises that were out of line. They thought the government should consider the wages and fringe benefit packages of small firms and of state-local government workers when trying to determine a fair rate for feds.

The Office of Personnel Management yesterday released a study of eight possible alternatives to the current industry-versus-government pay measurement system.

Using the current system, OPM says, feds would appear to be due an 18.5 percent catch-up-with-industry raise. Under the most restrictive proposed measurement, which would be based on estimates of minimum salaries needed to recruit and retain workers, federal pay would be chopped 12 percent. That is quite a range, obviously. Other possible systems produce other results. And each of them would be "accurate" if you accept the methodology used. The question is which one should--and will--the government use.

In the months ahead, the administration will propose changes in the pay-fixing system. Some of them could be made administratively. Others would require the approval of Congress. It is going to be a long, interesting year for feds.