Archaeological evidence provides the only basis for comparative research charting wealth inequality over vast stretches of the human past. But researchers are confronted by a number of problems: small sample sizes; variable indicators of wealth (including individual grave goods, the area of household dwellings or storage spaces); overrepresentation of the wealthy, or invisibility of those without wealth; and vastly different population sizes. Here, the authors develop methods for estimating the Gini coefficient—a measure of wealth inequality—that address these challenges, allowing them to provide a set of 150 comparable estimates of ancient wealth inequality.