President Reagan's new five-year budget projections leave no room for any of a variety of tax-cut plans he has promised to propose "at an early date."

Among those promises are a softening of the so-called "marriage penalty" by which married couples pay more than they would if they were single, tuition tax credits, indexing taxes for inflation, and easing inheritance taxes on family-owned farms and business.

Office of Management and Budget Director David Stockman said yesterday that exclusion of these items from the budget figures do not mean that the administration has abandoned the ideas, but he gave no clue as to where it would come up with the money to pay for them.

"[The ommission] only means that they won't be proposed at this time," Stockman said. "We have made it clear we want a clean bill" on depreciation and individual tax cuts.

In addition, the projections do not include continuation of some expiring tax proposals, such as exclusions for interest and dividends that Congress approved through calendar 1982 and that the administration would like to continue, but these also reduce revenues.

The only major tax changes taken into account are Reagan's proposed 10 percent across-the-board cuts for individuals and much faster depreciation for businesses.

Even with those large proposed tax cuts -- to total $44.2 billion for individual taxpayers in fiscal 1982 and $9.7 billion for depreciation -- taxes in dollar terms still would rise steadily for individuals and would dip only in the first year for businesses before starting upward again.

The 10-percent-a-year-for-three-years cuts would amount to an estimated $162.4 billion by fiscal 1986, and faster equipment and building write-offs would take $59.3 billion from businesses' tax bills that year.Still, total tax receipts would increase from an estimated $650.3 billion in fiscal 1982 to $940.2 billion in fiscal 1986, the administration figures show.

As a percentage of gross national product -- another way of measuring the nation's tax bite without the comparison being skewed so much inflation -- taxes are projected to drop from a fiscal 1981 level of 21.1 percent to 19.3 percent in fiscal 1984, about the same as it was in 1978. Under the Carter administration budget, they would have risen to 22.1 percent of GNP in fiscal 1982.

But the administration still is counting on its tax plan to "provide increased incentives for work and saving" for individuals and more capital expansion and productivity from business. This, in turn, is supposed to result in higher income, more tax receipts and contribute to a balanced budget in later years.

One somple change in the administration's economic assumptions boosted projected tax receipts by a much-needed $2 billion without the ordeal of trying to get legislation through Congress. OMB changed its projections on corporate profits for the next four fiscal years by $4 billion over the figures given in the Feb. 18 budget, resulting in boosted tax estimates of about $2 billion. This made up for Reagan's rejection of a proposed gasoline tax hike in the Feb. 18 budget figures, which President Reagan later rejected, and helped offset losses from other revised economic assumptions.

The Reagan budget-cutters lost a net of $2.5 billion by dumping all of the tax changes proposed by Carter in his January budget, which included a substantial gasoline tax increase.

The administration gained $3.5 billion on the outlays side in the Treasury Department budget by scraping Carter's proposal for refundable tax credits for business. That plan would have allowed some unprofitable businesses to get a check from the government when they didn't have enough tax liability to take all the investment tax credits they are entitled to.