America’s military bill for the Iran war has reached $ 45.1 billion, but even that figure does not capture the full cost of the conflict. The latest Pentagon estimate includes $ 43.6 billion in war-related spending through September 3 and another $ 1.5 billion for fuel, while repairs to damaged US bases and some indirect military expenses remain outside the calculation. The Pentagon provided the latest estimate to Congress on Friday, CNN reported, citing two sources familiar with the matter. The new figure shows a rapid rise from estimates released earlier in the summer.
The Pentagon had estimated the cost at $ 37.5 billion in July. The Congressional Budget Office separately calculated that the US Department of Defense had incurred about $ 38 billion in costs through August 1.
Where did the $ 45.1 billion go?
The latest Pentagon calculation consists of $ 43.6 billion in war-related costs through September 3 and another $ 1.5 billion in additional fuel expenditure, according to CNN.
That puts the reported military cost at $ 45.1 billion. It does not, however, amount to a final bill.
| Estimate | Amount | Period |
|---|---|---|
| Earlier Pentagon estimate | $ 37.5 billion | July 2026 |
| CBO estimate | About $ 38 billion | Through August 1 |
| Pentagon war-related costs | $ 43.6 billion | Through September 3 |
| Additional fuel cost | $ 1.5 billion | Latest estimate |
| Latest Pentagon total | $ 45.1 billion | Reported to Congress |
What is missing from Pentagon’s $ 45.1 billion figure?
One of the sources cited by CNN said the Pentagon calculation does not include the cost of repairing damaged US military bases and buildings.
Congress was also not given a detailed assessment of some indirect costs associated with military operations.
Those exclusions matter because the Pentagon’s number is already $ 7.1 billion above the CBO’s estimate through August 1.
CBO says another month could add $ 2 billion to $ 3 billion
The CBO published its own assessment on September 15. It estimated that the conflict had cost the Department of Defense about $ 38 billion as of August 1.
The figure covered the replacement of munitions used in combat and equipment lost in battle, additional flying hours, military operations and higher fuel costs.
The agency cautioned that there was “considerable uncertainty” around its calculation. It relied on government databases and public reports because the Department of Defense did not respond to its requests for information.
If fighting remained around the lower levels seen in May and June, the CBO estimated that another month would cost about $ 2 billion.
If combat returned to roughly the intensity recorded in July, that monthly bill could rise to $ 3 billion.
“Monthly costs could be higher still if the violence escalated further,” the CBO said.
Missile interceptors present another problem
There is another cost that cannot be measured simply by looking at dollars already spent.
The CBO said the heavy expenditure of missile-defence interceptors has reduced US inventories. Replacing them will take time, leaving the military with fewer interceptors available for several years.
The agency said such a shortage could become particularly serious if the US became involved in another conflict against an opponent with large numbers of ballistic and cruise missiles.
War cost is reaching Americans through energy prices
The effects of the conflict are also showing up outside the Pentagon budget.
Reduced oil and natural gas shipments through the Strait of Hormuz and disruption to Red Sea shipping have pushed global energy prices higher, according to the CBO.
The pressure has affected crude oil as well as petrol, diesel and jet fuel.
The CBO estimated that higher energy prices added 2.3 percentage points to the annualised rate of overall PCE inflation during the second quarter of 2026. PCE inflation stood at 5.3 per cent during that quarter.
For the first quarter of 2027, the agency now expects PCE inflation to be 0.5 percentage points higher than it projected in February. Core PCE inflation is expected to be 0.3 percentage points higher.
Trump administration sought another $ 87.6 billion
The Trump administration requested $ 87.6 billion in supplemental appropriations in June, according to the CBO.
Of that amount, $ 67.1 billion was requested for the Department of Defense. The budget office calculated that $ 42.3 billion appeared to be directly related to the Iran conflict.
Other expenses remain harder to calculate. The CBO said it could not estimate possible additional spending on diplomatic operations and foreign aid because those costs will depend on how the conflict develops.
From $ 38 billion to $ 45.1 billion in weeks
The comparison between the CBO and Pentagon figures gives a clearer picture of how quickly recorded costs have risen.
- The Pentagon estimated the conflict had cost $ 37.5 billion in July.
- The CBO calculated about $ 38 billion in defence costs through August 1.
- Pentagon war-related spending reached $ 43.6 billion through September 3.
- Another $ 1.5 billion in fuel brings the latest Pentagon estimate to $ 45.1 billion.
The $ 45.1 billion figure is therefore better read as the latest recorded Pentagon cost rather than the final price of the conflict.
How much further it rises will depend on the duration and intensity of the fighting, the weapons and equipment that need replacing, and expenses that have yet to enter the Pentagon’s current calculation.
