This study examines the relationships among students' perceptions of autonomy, competence, and relatedness, self-determined motivation, and achievement across two different undergraduate Calculus learning environments at the same institution. Furthermore, it also exposits how learning environments are not culturally or socially neutral by establishing clear evidence that one learning environment offered motivational support and associated achievement gains to specific demographic groups while diminishing motivation and achievement for others. To accomplish this, we applied constructs from Self-Determination Theory (SDT) within a quasi-experimental design (N = 6866), controlling for prior math knowledge, in both Calculus I and Calculus II over seven semesters. We use this information to advance the broad notion of student-centeredness and identify the role of motivational processes by which undergraduate Calculus learning environments function. We propose using motivational frameworks as a tool for defining and measuring student-centeredness relative to individual students, or student groups, rather than to students as a monolith.