Scholars have long conceptualized public support for war as the product of a cost–benefit calculation in which combat casualties factor significantly. This article argues that, when calculating the human costs of conflict, Americans care about more than just the number of war dead; they also care about the distribution of those casualties across society. Using two original survey experiments, we show that inequalities in sacrifice affect Americans’ casualty sensitivity. We find strong evidence that learning about socioeconomic inequalities in casualties in previous wars decreases Americans’ casualty tolerance toward future military endeavors. These effects are stronger for some mission types, particularly non-humanitarian interventions, than others. The effects are also concentrated among Americans from states that suffered high casualty rates in the Iraq War. Our results suggest that raising public awareness of inequalities in wartime sacrifice could significantly strengthen popular constraints on policy makers contemplating military solutions to future crises.