Federal job cuts proposed in President Reagan's budget revision look tough, and dramatic when compared with the job blueprints President Carter left behind in his final budget.But the figures -- Carter's and Reagan's -- are a bit misleading since both are based on assumptions and projections, not on the number of flesh-and-blood bureaucrats on the U.S. payroll.

Carter's last budget, for example, asked Congress to hire X number of federal workers in once place and cut X number in another. That budget "projected" U.S government employment levels for the end of this fiscal year (Sept. 30) and the end of the next fiscal year (Sept. 30 1982).

But Congress has not approved Carter's or Reagan's budget, so the data in them represent a certain amount of "creative accountancy." What you see it not necessarily what you get, and it certainly doesn't represent what you have. Example:

Reagan has called for substantial cuts in the non-Defense side of government. But his cuts, for the most part, are based on projected job totals (jobs that may or may not be filled now) left behind by Carter. Although some agencies will be required to RIF (lay off) employes, the magnitude of the cuts in the Reagan budget cannot be assessed since they are based on Reagan estimated cuts of Carter estimated increases.Neither total accurately reflects the makeup of the federal establishment.

For a somewhat better picture of where Reagan's budget would take the government if Congress approves, check the back pages of the budget. The part dealing with actual job totals (as of November 1980) and job levels Reaban is proposing for the end of the 1982 fiscal year (September 1982).

Even the "actual" figures are confusing since they don't reflect federal employment changes since November, and the effect of Reagan's solid hiring freeze. Here are the "actual" employment figures for federal agencies as of November 1980 and the budget recommendations for those same agencies (if Congress buys Reagan's figures) for the end of the 1982 fiscal year:

Agriculture, 85,400 (1980) to 84,000 (1982); Commerce, 29,300 to 39,900; Defense, 880,000 down to 878,700 by fiscal 1982. Based on the Carter budget, Reagan is raising Defense employment levels. Compared to reality, his plans would mean a slight decline in civilian employment in DoD.

Department of Education, 6,400 as of November 1980, down to 5,800 in 1982 under Reagan's revision; Health and Human Services, 136,400 down to 129,800; HUD, 15,600 down to 15,200.

Interior, 53,800 down to 52,800; Justice, 53,400 down to 52,800; Labor, 22,100 down to 21,000 at the end of fiscal 1982; State, 21,800 going up 100 jobs in fiscal 1982; Transportation, 68,800 down to 65,800; EPA, 10,700 to 10,400.

NASA, 22,600 to 21,600 by end of fiscal 1982 and Veterans Administration, down from 193,100 actual employes last November to 188,900 in 1982. GSA would drop from 32,300 to 30,100, ICA from 8,000 last November to 7,500, Office of Personnel Management, from 6,400 to 5,700.

The above numbers don't tell the full story because they do not reflect changes (most decreases in employment) since November. Many agencies that have frozen hiring for the past few months have dropped well below those November levels, so they have fewer cuts to make under the Reagan budget. Many agencies are setting up RIF plans, and officials say that some layoffs will be unavoidable where major program cuts are approved by Congress.

With cuts in the works, Uncle Sam ought to get on the ball to do something about replacement jobs for people who may be RIF victims. The irony is that Defense is on a hiring binge, while many other federal agencies are dusting off RIF procedures. It doesn't make sense for one agency to be hiring while another is firing people whose only crime is that they have little seniority.