The first 100 hours (H+100) of the US military operations against Iran are estimated to cost $3.7 billion, or $891.4 million each day, according to a commentary published in the Center for Strategic and International Studies (CSIS).

Some of these costs are already budgeted, but most ($3.5 billion) are not.

Future costs will depend mostly on the intensity of operations and the effectiveness of Iranian retaliation.

The costs are divided into three categories: operational costs (approximately $196 million total, with $178 million budgeted and the rest unbudgeted); munitions replacement (approximately $3.1 billion), none of which is currently budgeted; and replacing combat losses and repairing infrastructure damage (approximately $350 million), also unbudgeted.