The Congressional Budget Office estimates that U.S. combat operations against Iran cost the Department of Defense approximately $38.1 billion through August 1, 2026. The estimate covers replacing expended munitions and equipment lost in battle, increased flying hours, other operations and higher fuel costs.
CBO said another month of conflict would cost about $2 billion if violence remained at the relatively low levels seen in May and June, or about $3 billion if activity resembled July. Those are scenarios rather than a fixed forecast, and monthly costs could rise further if fighting intensified.
Replacing expended munitions was the largest component, at an estimated $21.7 billion. CBO also estimated $10.4 billion in additional flying-hour costs, $1.9 billion for equipment lost in battle, $1.5 billion in other operations and $2.7 billion tied to higher fuel prices; figures may not sum exactly because of rounding.
The estimate has significant limits. The Defense Department did not respond to CBO's requests for information, so the agency relied on government databases and public reporting. The total excludes costs that CBO could not estimate, including repairs to damaged U.S. bases, as well as costs borne by other federal agencies, normal military operating costs already in the budget and longer-term veterans' health and disability expenses.
