Iran War cost methodology, 120-day edition

By Stephen Semler

Operations

Estimated cost: $28.5 billion

The Congressional Budget Office (CBO) has a model for estimating the costs of operating various combat units. I adjusted the inputs to reflect the type and quantity of units participating in the Iran War, based on media reports and open-source intelligence. For example, USNI’s fleet tracker showed 15 US destroyers operating in the Arabian Sea, Persian Gulf, Red Sea, and Eastern Mediterranean at the start of the war. Each destroyer costs more than $4 million to operate per week. I adjusted the cost model’s inputs as additional US forces were deployed.

CBO’s data is calibrated to peacetime, and war makes everything more expensive — including war itself. To estimate how much more expensive, I analyzed military operations spending from 2003–14. To isolate the proportional increase in costs attributable to war, I measured operations spending in the supplemental budget relative to the Pentagon’s regular (“base”) budget rather than in absolute terms, to help control for cost growth not directly related to war (base operations spending rose by roughly 13% above inflation from 2003–14). I measured operations spending on a per–active-duty troop basis to help control for cost growth solely attributable to the scale of the Iraq and Afghanistan wars.

War increased operating costs by 33% on average from 2003–14, translating to a 1.33 cost multiplier, which I used to convert CBO peacetime costs to wartime costs. This multiplier could be too low. For example, the inflation-adjusted cost to operate three helicopters — CH-47D, UH-60L, and AH-64D — increased from 1998 (peacetime) to 2007 (wartime) by 140%, 262%, and 541%, respectively.

To account for the reduction in combat intensity following the ceasefire announced on April 8, I adjusted the wartime cost multiplier down to 1.10 for April 8–June 27, 2026.

Pre-war costs

The multi-week military buildup ahead of the war was the largest in decades. The cost to mobilize reservists ahead of the war is not implicitly captured in the CBO cost model or in the wartime cost multiplier (which is calculated on a per-troop basis), so I based the cost on the June 2025 war. Ahead of last year’s war, the US spent $2 billion activating 17,193 reservists (including $1.2 billion for the Army to mobilize 10,228 reservists to deploy to the Middle East), drawing funds made available by Sec. 1421 of P.L. 119-4. I estimated twice the reservist activation for this war (plus the 3.8% pay increase for military personnel enacted for 2026). I roughly estimated that the remaining cost of the multi-week pre-war buildup was equal to the cost of the current force posture operating for three weeks at a wartime cost multiplier of 1.10.

Weapons

Estimated cost: $46.7 billion

Missiles, bombs

During a May 14 hearing, CENTCOM commander Admiral Brad Cooper said the US had fired or dropped 13,629 munitions so far in the conflict. Based on news reports and official statements regarding strikes following the hearing, I estimated that 14,000 munitions had been dropped by June 27.

It’s possible that this figure is far too low. The last time the Pentagon provided a figure was on March 3, when it reported that the US had “struck nearly 2,000 targets with more than 2,000 munitions.” On March 4, Chairman of the Joint Chiefs of Staff Dan Caine told the press, “I know there have been a lot of questions about munitions…I want to tell you, teammates, as a matter of practice, I don’t want to be talking about quantities…we consider it an operational security matter.” In the early days of the war, the Pentagon disclosed the number of munitions it fired at Iranian targets, but stopped once the high cost of these munitions became a topic of public interest. This means that Cooper either broke with General Caine’s policy by disclosing the number of munitions or he meant to say “strikes” instead of “munitions.” In Cooper’s written testimony, he wrote that the US had carried out “over 13,500 strikes” during the war. If Cooper did in fact mean munitions, the result is fewer than 1.01 munitions per strike on average, which is far lower than the ratio of recent wars also fought entirely with precision-guided munitions:

Operation Inherent Resolve, Iraq and Syria, 16 Oct 2014–20 Jan 2017 (65,461 munitions / 39,608 targets = 1.65 munitions per target).

Operation Unified Protector, Libya, 31 Mar 2011–31 Oct 2011 (8,112 munitions / ~6,000 targets = 1.35 munitions per target).

If Cooper in fact meant “strikes” instead of “munitions,” the total number of munitions dropped or fired would actually be closer to 20,000 instead of the 14,000 munitions that served as the basis for this estimate.

I assumed one-third of the 14,000 munitions were long-range stand-off munitions and two-thirds were shorter range stand-in munitions. This assumption is based on official statements, media reports, open-source documentation of armament use, and historical analysis of past conflicts. Based on media reports, I estimated that 4,662 stand-off munitions had been used, including 1,130 Tomahawks; 90 PrSMs (equaling approximately the entire stockpile reportedly expended during the war); 930 ATACMS (the NYT reported in April that the US had fired more than 1,000 PrSM and ATACMs); 1,250 JASSM, JASSM variants, or others in the AGM-158 family of cruise missiles (in April, the NYT reported that the US had fired 1,100 JASSMs, but I adjusted the total upward to account for the additional time and therefore strikes since then, and to account for reports that the 1,100 figure was an underreported sum, considering that the US had reportedly committed nearly its entire inventory of JASSM-ERs to the conflict); 1,061 anti-radiation missiles, including the AGM-88 HARM, AARGM, and AARGM-ER

(During Operation Allied Force (Kosovo), US/NATO fired at least 743 HARMs (plus other anti-radiation missiles). Total munitions used by US/NATO forces: 28,018, of which 35% were precision-guided. I multiplied the 28,018 by 0.35, which equals 9,806 precision-guided munitions. To calculate the share of precision-guided munitions that were HARM, I divided 743 by 9,806 to get 7.6%, which I then multiplied by the estimated 14,000 precision-guided munitions used through 120 days of the 2026 Iran War, equaling 1,061. This is far fewer anti-radiation missiles used than in the first Gulf War); and 201 AGM-154 glide bombs.

For the shorter-range (and less expensive) munitions, I estimated 600 Hellfire missiles, based on the reported extensive use (and loss) of MQ-9 drones; 28 5,000lb GBU-72s; and 14 GBU-57 Massive Ordnance Penetrators, matching the quantity dropped on Iran in June 2025. For the remaining 8,696 munitions, I estimated a mix of 2,000-pound, 1,000-pound, and 500-pound precision-guided bombs based on their distribution during the first 30 days of the 2003 Iraq War (36%, 17%, and 47%, respectively).

This estimate excludes the unspecified number of LUCAS one-way drones fired as they were likely used predominantly to saturate enemy defenses rather than destroy specific targets, likely part of the “tens of thousands of pieces of ordnance” General Caine said were dropped on March 2 that were excluded from the Pentagon’s count on March 3.

Counter-missile

Iran reportedly fired 2,367 missiles during the first 120 days of the war (2,308 ballistic missiles and 59 cruise missiles).

To estimate the number of interceptors the US fired to down Iranian missiles, I first estimated the percent of Iranian missiles that survived the boost phase based on the June 2025 war (93%). Second, I referred to INSS data to determine the share of Iranian missiles targeting Israel and Gulf countries and US military bases in the Gulf (31% and 69%, respectively). Third, I estimated the number of remaining Iranian missiles that US, Israeli, and Gulf-state forces attempted to shoot down (in the Levant, 61%, based on the June 2025 war; in the Gulf, 80%, an estimated adjustment to the Levant’s percentage to account for the closer distance from Iran to targets in the Gulf). Fourth, I estimated the number of interceptors expended per incoming missile based on historical precedent and media reports. Finally, I estimated the mix of US interceptors used based on media reports, historical precedent, geography, and military assets in each theater. The cost of each interceptor reflects the FY2027 flyaway unit cost from official procurement documents.

The Washington Post reported in May that the US had fired more than 200 THAAD and more than 100 SM-3 and SM-6 interceptors defending Israel, while Israeli forces had fired fewer than 100 Arrow and 90 David’s Sling interceptors, meaning the US had shouldered close to two-thirds of the missile defense burden, while JD Vance said it was two-thirds. During the June 2025 war, the US shouldered 70% of the burden, with the US firing more than 150 THAAD and 80 SM-3 interceptors.

To estimate the US missile defense burden for the 2026 war, I averaged the share implied by the Washington Post report, JD Vance’s figure, and the percentage from the June 2025 war, arriving at 67%. I then estimated that the US expended 1.41 interceptors on average per Iranian missile engaged. This average is based on the reported ratio during the October 2024 missile barrage, June 2025 war, and the figures reported by the Washington Post and stated by Vance.

I estimated that the US fired 384 interceptors defending Israel through June 27 during the 2026 war. Based on the 2025 war, I estimated that 254 of those interceptors were THAAD and 131 were SM-3 and SM-6. Based on the fact that SM-3s were used exclusively to defend Israel during the 2025 war, I estimated that 90% of the SM variants were SM-3 and 10% SM-6 (or SM-2), or 118 and 13, respectively.

To estimate the number of interceptors the US expended defending Gulf countries and its military bases in the Gulf, I assumed an interceptor:missile ratio of 2.15:1, based on the June 2025 interception of Iranian missiles headed for al-Udeid Air Base in Qatar and the US war with the Houthis. (US forces used 30 Patriot interceptors to shoot down 13 Iranian missiles fired at al-Udeid Air Base that Iran warned were coming, and averaged two interceptors for each Houthi missile from 2024–25).

The resulting estimate was 2,105 interceptors fired by the US in this theater, including 1,300 Patriot interceptors (per NYT May report). For the remaining 38% of the interceptors, I estimated 5% THAAD, and 33% SM-3/-6/-2, including 30% SM-3 and 70% SM-6/-2 (which have the same replacement cost, as the SM-6 replaces the SM-2).

Counter-drone

Iran reportedly launched 5,348 attack drones in the first 120 days of the Iran War, 14% directed at Israeli targets and 86% at Gulf targets.

During the June 2025 war, 73% of the drones Iran launched at Israel were considered a threat and engaged by US and Israeli forces, with the rest deemed non-threatening and not engaged.

I estimated that the US shot down 20% of the threatening drones launched at Israel (reflecting the 2025 war), and assumed a 2:1 interceptor:drone ratio on average (which may be generous, considering it took two AIM-9X missiles to shoot down a balloon over Lake Huron after the first one missed).

All told, I estimated the US expended 196 interceptors to fell Iranian drones launched at Israel.

I estimated the mix of munitions employed based on the reported use during Operation Rough Rider and media reports about the current conflict. This includes 40% APKWS (per General Kurilla testimony); 25% AIM-9X Sidewinder; 10% AMRAAM; 5% Merop, Bumblebee, or Coyote interceptors; 14% SM-6/-2 interceptors (I believe the number of SM-6/-2s expended on Iranian drones has been vastly understated. A CBS report from Feb 2024 indicated how heavily the US Navy relied upon the SM-6/-2 as a counter-drone munition. The Navy said it had shot down 20 Houthi ballistic missiles and more than 130 Houthi drones from October 2023 – February 2024. In the course of doing so, the Navy revealed that it had expended more than 100 SM-2/6s (in addition to other counter-drone munitions, like air-to-air missiles). Assuming a 2:1 interceptor:missile ratio, the US used more than 60 SM-2/6s — two-thirds of the total SM-6/-2s fired — shooting down drones); and 1% Patriot interceptors (I suspect US forces have used Patriot interceptors against drones far less frequently than implied in the media), and 5% other less expensive methods (e.g., C-RAM, Apache helicopter cannons, electronic countermeasures), which aren’t factored into the interceptor total.

I assumed the same mix of munitions for the Gulf, but I estimated that 90% of the drones launched were considered threatening and that 70% of those were shot down by the US, to account for the reduced distance to targets, addition of US targets, and relative lack of capacity of Gulf military forces. I estimated that the US expended 4,967 interceptors on Iranian drones targeting Gulf countries and US military assets in the region.

Losses

Estimated cost: $20.3 billion

The Pentagon refuses to comment on damaged bases: “We do not discuss battle damage assessments for operation security [sic] reasons. Our forces remain fully operational, and we continue to execute our mission with the same readiness and combat effectiveness.”

The American Enterprise Institute (AEI) estimated $5 billion in damage to 70 US military structures at 11 US military bases during the Iran War. My estimate is extrapolated from this analysis, as it’s among the most detailed and credible when cross-referenced with official facilities pricing data. However, AEI applied a 30% cost contingency factor to account for security/logistics problems emanating from the war and closure of the Strait of Hormuz, as well as increased fuel costs. I removed that 30% surcharge due to the tentative ceasefire and tentative reopening of the Strait, though I recognize some of the challenges and thus increased costs that AEI factored in may still apply.

In May, the Washington Post reported that its partial count found 217 damaged or destroyed structures, 3.1 times the number factored into AEI’s cost estimate, at 15 US bases. In June, a BBC investigation found that there was actually damage to 20 US military bases in the region.

To convert that to an estimated number of damaged or destroyed structures, I divided the Washington Post’s 217 damaged or destroyed structures by the 15 military bases it analyzed to get an average number of damaged or destroyed structures. To account for the 5 additional damaged bases uncovered by the BBC, I multiplied that average by 5 and added the total (72) to the 217 structures reported damaged or destroyed by the Washington Post for a total of 289. The factor by which that 289 figure is larger than the 70 reported by AEI equals 4.1, which I multiplied by $3.5 billion (the downward adjusted total for 70 damaged or destroyed structures from the AEI analysis) to arrive at $14.5 billion in estimated damage to structures at US military bases.

Because AEI’s estimate thankfully did not include damage to US military equipment (it only assessed damaged military infrastructure), I was able to calculate those damages separately, using media reports corroborated by open-source intelligence, including satellite imagery. To estimate damaged equipment, I assumed the cost equivalent to a minimum class A mishap, or $2.5 million. This is likely an underestimate. Damaged equipment includes: 1 HH-60 helicopter, 1 F-35, 1 MQ-9, 10 KC-135s.

The cost of destroyed equipment refers to the item the Pentagon plans to replace the lost unit with. Sometimes it’s the same thing. In other cases, it’s a more advanced and much more expensive variant. What follows are the battlefield equipment losses with the total replacement cost in parentheses: 4 F-15E aircraft (F-15EX replacement cost, $431M), 1 E-3 Sentry aircraft (E-7 replacement cost, $715M), 1 A-10 aircraft (F-35 replacement cost, $126M), 1 CH-47F Chinook helicopter ($51M), 1 MQ-4C Triton drone ($186M), 2 MC-130J aircraft ($519M), 2 KC-135 aircraft (KC-46A replacement cost, $206M), 28 MQ-9 drones ($688M), 2 MQ-1 drones, 1 AH-64 Apache helicopter ($43M), 4 MH-6M helicopters, and 3 mobile AN/TPY-2 radars ($705M).

The figures refer to the per unit flyaway cost via the Pentagon’s 2027 budget materials, specifically, procurement documents for the Army, Navy (including Marine Corps), Air Force, Special Operations Forces, and Missile Defense Agency.

Subsidies

Estimated cost: $2.9 billion

The Trump administration expects US taxpayers to fund not only its own military adventurism but Israel’s as well. Earlier this year, Congress approved more than $4 billion in military aid for Israel, including $702 million from the Pentagon budget (missiles, $500 million; anti-tunneling, $80 million; counter-drone, $75 million; “emerging technology,” $47.5 million) and $3.3 billion from the State Department, which is for a military aid program that functions as a gift card for Israel to spend on US weapons (though Israel is allowed to spend a portion of it on weapons from Israeli companies).

From the Pentagon budget, I excluded the anti-tunneling amount but included the other aid (“cooperative”) programs. From the State Department budget, I included $2.3 billion of the $3.3 billion in aid. This figure is based on US arms “sales” to Israel funded by that military aid, authorized this year, and germane to the war with Iran. This includes a $209 million sale of 10,000 500-pound bombs; a $151.8 million sale of 12,000 1,000-pound bombs (part of which transferred directly from US stock); a $992 million sale of 10,000 Advanced Precision Kill Weapons System rounds; a $298 million sale of up to 5,000 GBU-39 small diameter bombs; and another 2,166 GBU-39s expedited from a larger $6.75 billion sale, for an estimated cost of $129 million.

To estimate the value of “under-threshold” sales — sales that don’t exceed a value threshold to trigger congressional notification and thus are not made public — I took the amount of under-threshold sales to Saudi Arabia and United Arab Emirates from 2017–19 disclosed in a government watchdog investigation and divided that figure by the total number of foreign military sales and direct commercial sales for the same three years as reported in the annual Section 655 report and Historical Sales Book ($11.2 billion divided by $49 billion) to arrive at 23%. I applied that 23% to the above-threshold sales to Israel to estimate the value of under-threshold sales to the country during the 2026 war ($1.8 billion / (1 – 0.23)), totaling $2.3 billion. I then added that total to the $623 million in Pentagon-funded aid to get $2.9 billion.

Other (War costs to nonmilitary US agencies)

Estimated cost: $4.8 billion

This figure is based on the stated costs and justifications disclosed in the Trump administration’s supplemental funding request to Congress on June 24, 2026.