Iran War cost methodology

By Stephen Semler

Operations

Estimated cost: $15.8 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. 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 8–28 (21 of the 60 days of the war analyzed for this estimate).

Prewar 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 peacetime cost of the current force posture operating for two weeks.

Weapons

Estimated cost: $41.2 billion

Missiles, bombs

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.

The last time the Pentagon provided a figure was on March 3. 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.”

However, the Pentagon still discloses the number of targets it has struck, albeit imprecisely, which can be used to infer munition usage. I based my estimate — 1.36 munitions per target — on the average munition to target ratio of three recent wars:

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

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

-Operation Iraqi Freedom (first 30 days only), Iraq, 19 Mar 2003–18 Apr 2003 (29,199 munitions / 19,898 targets = 1.47 munitions/target, which I adjusted to 1.01 munitions/target to account for non-precision-guided munitions, though this is likely an over-correction.)

On April 8, the Pentagon reported that the US had struck more than 13,000 targets in Iran. For a precise figure, I conservatively estimated 13,300, which I multiplied by 1.36 to estimate the number of US munitions. I assumed 25% were the very expensive, long range “stand off” munitions used heavily in the first few days of the war and 75% were the less expensive, short range “stand in” munitions the US reportedly transitioned to as the war progressed.

The US military reportedly fired more than 1,000 sea-launched Tomahawk missiles ($3.7M each), nearly 1,000 ATACMS land-based missiles, and its entire stockpile of PrSM land-based missiles (~90, $1.8M, average of increment 1 and 2 variants), meant to eventually replace the ATACMS. I estimated the US used 1,000 AGM-88 HARM or equivalent air-to-ground missiles ($2.7M each) — nearly the number used during Operation Desert Storm — and 372 Joint Stand Off Weapon air-to-ground munitions, based on media reports and forensic weapon analysis.

For the less expensive air-dropped bombs, 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). I also estimated 1,000 Hellfire missiles were used based on the reported extensive use (and loss) of MQ-9 drones.

All told, the US expended an estimated $12.8 billion in missiles and bombs during the first 60 days of the Iran War. This estimate excludes the unspecified number of LUCAS one-way drones fired as they were likely used predominately 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 2,245 ballistic and cruise missiles during the first 60 days of the war. During the June 2025 war, 7% of the missiles Iran fired failed at launch (546 out of the 588 total launched at Israel and at al-Udeid, the US military base in Qatar), and US and Israeli forces attempted to shoot down 62% of the remaining missiles (322 out of 546), with the rest deemed non-threatening. For the 2026 war, I assumed that half of the non-threatening missiles in last year’s war were considered threatening in this year’s, due to the reduced distance between Iran and US military bases in the Gulf, which in term reduces the time to determine a missile doesn’t pose a threat.

This results in an estimated 1,691 Iranian missiles that were engaged with US and coalition interceptors. I estimated that 1.7 interceptors were fired at each Iranian missile, on average. Although 1.1 were reportedly used per Iranian missile in the June 2025 war (361 interceptors for 339 missiles), 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 US reportedly fired 72% of the interceptors during the June 2025 war (Israel fired 101; the US fired 230 defending Israel and 30 defending al-Udeid). For the 2026 war, I estimated conservatively that the US would assume half of the non-US burden in 2025, given Iran primarily targeting US military bases, and the relative decline in air defense capacity of Gulf countries compared to Israel. This results in an estimated 2,473 interceptors fired by US forces.

To estimate the specific mix of interceptors used, I assumed a reverse of the mix of the SM, THAAD, and Patriot interceptors used in the June 2025 war, due to the increased targeting of US military bases, where the latter is more prevalent. I adjusted this ratio slightly due to the reported “more than 1,200” Patriot interceptors fired by US forces in the war’s first 60 days. Specifically, I assumed 1,250 Patriot, 457 SM-6, 304 SM-3, and 462 THAAD interceptors were fired by US forces.

Counter-drone

Iran reportedly launched 5,191 attack drones in the first 60 days of the Iran War.

During the June 2025 war, 73% of the drones Iran launched were engaged by US and Israeli forces with the rest deemed non-threatening and not engaged. For the 2026 war, I estimated the share of non-threatening drones was cut in half due to the significantly shorter distance from Iran to US military bases in the Gulf. The US reportedly shot down 18% of Iranian drones launched during the June 2025 war, but those drones exclusively targeted Israel. For the current war, I quadrupled the share intercepted by US forces given Iran’s targeting of US military bases. This leaves an estimated 3,169 Iranian drones shot down by US forces.

I assumed two munitions were used on average per drone — generous, as it took US fighter aircraft two Sidewinder missiles to shoot down a balloon over Lake Huron in 2023 — resulting in an estimated 6,338 munitions used to fell Iranian drones.

The Advanced Precision Kill Weapons System (APKWS) was reportedly used by US forces to down 40% of Houthi drones during Operation Rough Rider, Trump’s 2025 escalation of Biden’s war in Yemen and the Red Sea. I assumed its use increased to 50% to shoot down Iranian drones during the current war ($51K each). I estimated that staple air-to-air missiles like the AIM-9X Sidewinder ($622K each) and AIM-120 AMRAAM ($1.4M each) combined to be used nearly as often — 30% and 5%, respectively — with 5% each for SM-2s (SM-6 replacement cost, $6.3M each), Coyote interceptors, and various less expensive anti-drone countermeasures (e.g., C-RAM, Apache helicopter cannons, electronic countermeasures).

Losses

Estimated cost: $11.9 billion

The American Enterprise Institute (AEI) estimated $5 billion damages to 11 US military bases during the Iran War. However, a later CNN analysis revealed that at least 16 were actually damaged — the majority of US bases in the region — far more than the Pentagon had disclosed or was willing to acknowledge. The Pentagon refused to comment on damaged bases, telling The Hill: “We do not discuss battle damage assessments for operation security reasons. Our forces remain fully operational, and we continue to execute our mission with the same readiness and combat effectiveness.” I extrapolated the AEI figure to account for the additional five bases, increasing the figure to $7.3 billion.

However, because the AEI estimate only counted damaged or destroyed infrastructure. To estimate damaged equipment, I assumed the cost equivalent to a minimum class A mishap, or $2.5 million. This is likely an underestimate in most if not all cases, but there is a lack of information on the extent of the damage in most if not all cases. Damaged equipment includes: one E-3 Sentry aircraft, two HH-60 helicopters, one F-35, six KC-135s.

The cost of destroyed equipment is based on 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: four F-15E aircraft (F-15EX replacement cost, $431M), one E-3 Sentry aircraft (E-7 replacement cost, $715M), four MH-6M helicopters ($40M), one A-10 aircraft (F-35 replacement cost, $126M), one CH-47F Chinook helicopter ($51M), one MQ-4C Triton drone ($186M), two MC-130J aircraft ($519M), two KC-135 aircraft (KC-46A replacement cost, $206M), 24 MQ-9 drones ($688M), and two 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 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 called Foreign Military Financing 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 all aid programs except the $500 million in missile aid, as that funds the production of Israeli interceptors, which is one of Israel’s largest war costs.

From the State Department budget, I included $2.4 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 for 10,000 500-pound bombs, and a $151.8 million deal for 12,000 1,000-pound bombs, part of which transferred directly from US stock. Secretary of State Marco Rubio designated both these sales as emergencies on March 12, plus a portion of one other (for 2,166 250-pound bombs), in an effort to bypass the standard congressional review period. Both these sales are funded by Foreign Military Financing.

A $992.4 million arms sale to Israel was announced on May 1, which Rubio also designated as an emergency. The announcement itself doesn’t say how the sale is funded, but it’s very likely funded by US military aid. For government-brokered arms sales to Israel, 90% are funded with Foreign Military Financing. It’s likely the sale announced on May 1 is one of them, given the emergency designation and germaneness of the weapons included in the sale to the Iran War (10,000 Advanced Precision Kill Weapons System, or APKWS, rounds, emerged as the most popular munition employed by US forces for shooting down Houthi and later Iranian drones, and appears to be becoming a staple in the Israeli military’s arsenal too).

I estimated that these sales represented 60% of the US-funded arms transfers to Israel related to the Iran War. The other 40% ($960 million) are “under threshold” sales, which are sales that don’t exceed a value threshold to trigger congressional notification. As demonstrated by the Biden administration, sales that would otherwise trigger congressional notification can be broken up into many small sales to avoid public scrutiny. The Trump administration is likely following suit, for similar reasons. Given the constant flow of US shipments into Israel documented throughout the war, the $960 million figure is likely an underestimate.