Across disciplines, scholars strive to better understand individuals’ milieus—the people, places, and institutions individuals encounter in their daily lives. In particular, political scientists argue that racial and eth- nic context shapes attitudes about candidates, policies, and fellow citizens. Yet, the current standard of measuring milieus is to place survey respondents in a geographic container and then to ascribe all that container’s characteristics to the individual’s milieu. Using a new dataset of over 2.6 million GPS records from over 400 individuals, we compare conventional static measures of racial and ethnic context to dynamic, precise measures of milieus. We demonstrate how low-level static measures tend to overstate how extreme individuals’ racial and ethnic contexts are and offer suggestions for future researchers.