The Carter administration estimated yesterday that the proposed B-1 bomber fleet will cost $24.8 billion to procure - at $101.7 million per plane and $40 billion over the next 20 years.

The Pentagon said that the B-1 would be the first combat aircraft in history to break the $100 million cost barrier. The $40 billion total cost estimate, which includes operating expenses, came from the White House in response to quesions submitted to President Carter.

AIr Force leaders want to build 244 of the new bombers.

During his presidential campaign Carter called the plane "wasteful." But as President, he has refused to rule out full production of the bomber.

"The B-1 is an example of a proposed system which should not be funded and would be wasteful of taxpayer's dollars," Carter told the Democratic Platform Committee on June 12, 1976.

Yesterday, Carter wrote a national coalition trying to shoot down the bomber that "I expect to make a decision on whether or not to produce the B-1 this summer."

The President said Defense Secretary Harold Brown's current review of ways to modernize the American long-range bomber force "will be an important factor in my decision" as will "changes in the world situation such as an abrogation of current strategic arms limitation treaties."

If Carter does order the B-1 bomber into production, charged one of the leaders of the national coalition yesterday, It will be a breach of faith."

Nancy Ramsey, representing the Women's International League for Peace and Freedom, made that charge during a press conference called by a coalition of 36 national organizations called National Campaign to Stop the B-1 Bomber.

She and other coalition spokesmen said the United States does not need a new bomber; that the billions it would take to build it could provide more jobs if channeled into nondefense fields; and that the B-1 would be the greatest fuel guzzler of all time because "it gets 440 yards on a gallon."

Coalition staffer Robert Brammer said the organization submitted 14 questions to Carter on Feb. 23 and received his responses yesterday in a meeting with presidential aides at the White House.

Carter said in his responses that the $40 billion estimate covers the cost of developing and producing 244 B-1 bombers; operating them for 20 years, and buying and operating the KC-135 tankers they would need for aerial refueling.

The $40 billion estimate, Carter said, is in "constant," fiscal 1978 dollars - meaning no allowance was made for future inflation, which would add to the cost.

Jemy Stone, representing the Federal of American Scientists which is int he anti-bomber coalition, predicted the real cost of the 244 B-1 bomb over the next 20 years would be around $90 billion.

Even $40 billion, Stone said, The B-1 won't be "the biggest single military protect since the Chinese Wall." He said there is no need to rush into buying the B-1 because the B-52 bombers now flying will last "into the 1990s."

The $2 billion Pentagon figure released yesterday on the B-1 does allow for future inflation but not operating costs nor the price of buying tankers for the bomber. Specifically, the latest Pentagon estimate is $24,825,700,000 for design and building 244 B-1 bombers, or $1.7 million each.

Rockwell International is building the bomber under a limited production contract signed Dec. 2, 1976. It calls for building three production models of the bomber. Three test version of the plane are already flying and a fourth test model is under construction.

The Air Force considers the B-1 a vital addition to the nation's strategic deterrent; says it would be harder to shoot down than the aged B-52 goes farther on less fuel than the B-52, and can carry more weapons from the United States to Soviet Union than the B-52.

The B-1 has wings that can be swept back and forth for maximum speed and fuel efficiency, would fly faster than the speed of and at high altitude on the way to Soviet targets and then penetrate the Russian land mass by flying in at tree-top level to dodge radar defenses.

The B-1 can carry bombs, nuclear-tipped supersonic assiles and the subsonic cruise missile in its bomb bays.

The Pentagon's current B-1 contract with Rockwell expires June 30. Carter could simply extend it for a limited period of time and declare he wants to keep building the bomber until he determines whether the Soviets are willing to reduce strategic weapons under an arms agreement.