This study investigates how the use of calculators during high school mathematics courses is associated with student performance in introductory college calculus courses in the USA. Data were drawn from a nationally representative sample of 7087 students enrolled in college calculus at 134 colleges and universities. They included information about students' demographics, standardized test scores, and high school mathematics course enrollment and performance. Factor analysis reduced ten items describing high school calculator usage to two composites: how extensively calculators were employed and teacher-imposed restrictions on their use. Hierarchical linear models predicted students' college calculus grades, reported by their professor, while controlling for differences between colleges and student backgrounds. The more extensively students had used calculators in high school, the lower their grade in college calculus. However, students earned higher college calculus grades to the extent that their high school teachers had limited calculator use on quizzes and exams and had restricted calculator use until paper-and-pencil methods had been mastered, which offset the negative association of extensive calculator use with grades. The effect sizes of both calculator composites were very small. Overall, the findings raise doubts about any substantial long-term effects on college mathematics performance of calculator use in high school.