Americans have spent an estimated $102 billion more on gasoline and diesel since the Iran war began at the end of February, or about $780 per household, according to Brown University’s Watson School. Its real-time tracker compares observed fuel prices with a historical no-war counterfactual, estimating $56.2 billion in additional gasoline costs and more than $46 billion in diesel costs. Six months into the conflict, diesel surpassed $6 a gallon for the first time on record and gasoline remained near its highest levels since 2022, although elevated fuel prices showed limited spillover into broader consumer prices such as food and clothing. Brown’s estimate is narrower than Moody’s Analytics Chief Economist Mark Zandi’s earlier calculation of about $115 billion in broader energy costs, or $860 per household, which included jet fuel. President Donald Trump has said prices will fall after the conflict ends, while acknowledging oil prices may not decline until after the U.S. midterm elections in November. The White House has pointed to expanded refining capacity and continued control of the Strait of Hormuz as ways to restore prices to pre-conflict levels.