Iran war cost hits $38 billion, forecast to rise $3 billion a month, US agency says

The more than six-month-old US war against Iran has cost the US $38 billion so far, and that amount is projected to rise by $3 billion a month, the US Congress’s nonpartisan bookkeeper reports, as the Trump administration searches for ways to end the conflict and reopen the vital Strait of Hormuz.

The war is expected to increase inflation by 0.5% in the first three months of 2027, according to the Congressional Budget Office accounting, which totaled expenses through August 1.

The mounting costs have strained US munitions stockpiles and driven up energy prices, raising concerns about the country’s ability to respond to other potential conflicts and adding pressure on an already stretched federal budget.

The cost is close to the $37.5 billion that Defense Secretary Pete Hegseth reported at a Senate hearing on July 21.

The budget office says the majority of the costs stem from the rapid drawdown of munitions, estimating that it could take five years to replenish US stockpiles. Reuters reported in August that the US had used “virtually all” of its long-range precision missiles during the war.

The Department of Defense did not cooperate with congressional financial auditors, CBO reports.

Representatives from the White House and Department of Defense do not immediately respond to requests for comment.

The report does not include costs of recent strikes on commercial vessels in the Strait of Hormuz and attacks on US military installations in the region. It also does not factor in the borrowing expenses associated with financing the war, which could add tens of billions of dollars to the total cost.