Pharmacy calculations is a course that can be challenging and is often associated with student anxiety about assessments and grades. This study was conducted to determine if student anxiety would be reduced in pharmacy calculations using self-paced, multiple-attempt assessments. Self-paced, multiple-attempt assessments were presented to students as graded practice modules and as examinations. Pre-post surveys were used to measure student anxiety in pharmacy calculations. Module performance indices and exam performance indices were correlated with course grade outcomes. Fifty-four students participated in pre-surveys and forty-eight students participated in post-surveys. Westside Test Anxiety Scale survey results indicated use of self-paced, multiple-attempt assessments reduced students' perceived anxiety about pharmacy calculations. Student comments about assessment methods were predominately positive. Course grades strongly correlated with module mean scores and high scores, and strongly correlated with mean exam scores. A negative correlation between course grades and belated module attempts alluded to harmful association between student procrastination and course performance in weaker students. Self-paced, multiple-attempt assessment was associated with improved perception of student test anxiety about pharmacy calculations. With care taken to limit student procrastination, use of these types of assessment could be an effective means of improving student comfort while promoting mastery of the subject.