President Reagan's elaborate four-day inauguration celebration last year cost $16.3 million, making it the most expensive in U.S. history.

Nevertheless, the 1981 Presidential Inaugural Committee was able to cover the costs, raising almost $17.3 million from contributions and the sale of memorabilia and tickets to inaugural events, an audit released yesterday by the committee shows.

The committee reported a profit of about $1 million, most of which will be used to fund an Inaugural Scholars Program to help disadvantaged youths.

Reagan's inaugural cost more than four times as much as President Carter's $3.5 million, five-day celebration and was twice as expensive as the $8 million that Reagan's inaugural committee originally predicted.

Robert K. Gray, a Washington public relations expert who co-chaired the inaugural committee, said the audit proved Reagan's inauguration was a "financially solid event, run on a business-like basis."

"This was free enterprise at its best. It paid for itself, offered more free events to the general public than ever before, and did not involve any government money," said Gray.

Charles Z. Wick, now head of the International Communication Agency, was Gray's co-chairman.

While the committee technically did not spend government funds, the inauguration was indirectly subsidized by the government.

Reagan's committee was the first to win tax-exempt status for contributions to a separate Inaugural Trust Fund created by the committee to raise money for the construction of a parade viewing stand for the president and the press and a fireworks show.

The fund was granted tax-exempt status because both those expenses were for "public purposes" and because any excess contributions were to be used for a scholarship fund.

The audit showed that more than $1 million in tax-deductible contributions were given to the fund, which spent nearly $900,000 to build the reviewing stand and buy fireworks.

Gray said the inaugural committee transferred about $855,000 of its profit to the trust fund for the scholarship program, which still is in the planning stages.

He said the inaugural's expense was caused by the "great number of events we planned."

Reagan's inaugural was the first to have elaborate opening and closing ceremonies free to the public and the first to televise closed-circuit broadcasts of its 10 inaugural balls to more than 50 cities where local residents had bought tickets to inaugural celebrations.

The committee also hosted dozens of receptions and flew in 43 Hollywood entertainers to perform at a televised Capital Centre gala.

The tickets to some events were high--as much as $500. Even so, the committee refunded $1.4 million of the $12.3 million it raised from ticket sales because of overselling.

Officials estimate that more than 3,000 ticketholders were turned away from various events.

The committee netted another $2.3 million from the sale of inaugural license plates, ties, cuff links and other doodads.

At the start, the committee said it wanted to make Reagan's inaugural "more dignified" than President Carter's five-day "Y'all come, people's celebration."

Carter's committee said it intended to "bury the concept of the Imperial Presidency forever" when it limited the price of inaugural tickets to $25 each and made nearly all its events public.