On February 28, when the United States and Israel launched their attack on Iran, the Trump administration reportedly expected to win the war within a few days and believed Iran would surrender. But as the conflict unfolded, officials soon realized their calculations were wrong and that they were facing a strong, disciplined adversary. Iran struck U.S. bases across the Middle East, forcing U.S. forces to leave some of them, and damaged or brought down numerous U.S. drones and warplanes. The United States soon recognized that it had entered a costly conflict,  with expenses mounting faster than anticipated.

Pentagon figures obtained by Reuters show that the U.S. military’s estimated cost of the war with Iran has climbed above $47 billion—more than 25 percent higher than the $37.5 billion estimate Pete Hegseth gave in July. The latest figure is an unpublished accounting of the war’s costs, and it is already more than $3 billion above the Pentagon’s approximately $43.6 billion estimate in early September. 

Replacing munitions accounts for the largest share of the bill: more than $29 billion is projected for weapons expended during the conflict. The estimate also sets aside more than $6 billion to replace lost military equipment, including aircraft and drones. Other costs include the expense of carrying out operations, from flight activity to cyber support. 

A separate U.S. Central Command estimate dated October 16 and shared with Congress offers more detail. It lists nearly $12 billion in incremental costs associated with military action, and $7.6 billion for Air Force support in the theater, including deployed personnel, airlift, bases, communications and transportation. Those figures still leave out a major potential expense: repairing U.S. military bases damaged by Iranian missile and drone attacks. The cost of that reconstruction has not been clearly incorporated into the public estimates. 

The growing price tag comes alongside mounting losses to U.S. aircraft and equipment. A Congressional Research Service tally updated on October 5 listed 81 U.S. military aircraft destroyed or damaged since the war began on February 28, nearly double the 42 recorded in its May tally. 

The tally also covers a range of manned aircraft, including fighter jets, refueling aircraft, surveillance planes and special operations aircraft. The losses and damage have occurred in combat, in attacks on U.S. bases and in other incidents. Taken together, the cost estimates and aircraft tally point to a conflict placing pressure on U.S. weapons stocks, equipment and regional facilities,while the full bill remains uncertain because base-repair costs are still outside the published accounting.