Iran war costs have reached $45.1 billion, according to a new Pentagon estimate delivered to Congress, adding to the growing financial burden of the conflict and exceeding an earlier projection from the Congressional Budget Office.
The Pentagon told lawmakers that the cost stood at $43.6 billion as of September 3, with another $1.5 billion attributed to additional fuel expenses, according to sources familiar with the briefing. The figures make the latest Pentagon estimate the highest official assessment of the war’s direct costs so far.
The figure does not represent the full cost of the conflict. The Pentagon’s estimate does not include the expense of repairing US military bases and other buildings damaged during the fighting. It also does not provide the detailed accounting of indirect military costs that lawmakers have requested, leaving the eventual financial impact of the war potentially higher.
The latest number comes just days after the Congressional Budget Office estimated that the conflict had cost the Defense Department about $38 billion through August 1. The CBO said the figure covered expenses including replacement of munitions and equipment, additional flying hours, fuel and other operational costs.
The difference between the two estimates partly reflects their different reporting dates and methodologies. The Pentagon’s $45.1 billion figure extends into September, while the CBO estimate stops at August 1. The Pentagon had previously put the cost of the war at $37.5 billion in July, meaning its latest assessment represents a substantial increase in a relatively short period.
The CBO has warned that the cost will continue to rise as long as fighting continues. Depending on the intensity of military operations, the budget office estimated that the conflict could add between $2 billion and $3 billion to US costs each month, with the possibility of higher spending if the fighting escalates.
Much of the financial burden is tied to the use and replacement of military equipment and munitions. The CBO estimated that replacing expended munitions accounted for a significant share of the $38 billion incurred through August 1. Its estimate did not include the cost of repairing damaged US facilities, either.
The financial consequences are also extending beyond the Pentagon’s budget. The CBO said disruptions linked to the conflict have pushed energy prices higher, increasing pressure on consumer prices. It projected that inflation in the first quarter of 2027 could be about 0.5 percentage points higher than the agency had projected in February 2026 as a result of the conflict’s effects on energy prices.
The higher costs come as Washington faces difficult choices over additional funding for the conflict and the replacement of military equipment already used in combat. The CBO said the Defense Department had sought tens of billions of dollars in supplemental funding, while also warning that continued fighting would keep adding to the financial burden.
For Congress, the Pentagon’s latest estimate provides a more current picture of the cost of the war, but it is still not a final bill. Repair costs, some indirect expenses and other longer-term consequences remain outside the $45.1 billion figure. As the conflict continues, the number is likely to change again, making the eventual cost of the war considerably harder to measure than the headline figure currently presented to lawmakers.
