The aim of this retrospective study was to show the use of dimensional analysis increased associate degree nursing students’ mathematical computation competency and may reduce nursing medication errors in practice. A recent report compiled by Mackary and Daniel from John Hopkins, stated that medical error is the third leading cause of death in the United States . The most commonly cited estimate of annual deaths from medical error in the United States is a 1999 Institute of Medicine (IOM) report which is possibly limited and now outdated . Medication errors contribute to patients’ deaths, whereas nurses administer either incorrect medication, or incorrect doses of medication. Human error is inevitable, however designing safer systems to administer medication such as the use of a bar code system, and the standardization of academic medication calculation teaching may decrease these errors. According to a report from a major insurance company that insures a large percentage of nurses, malpractice claims in nursing is on the rise . Claim settlements and court judgments for 2015 against nurses include: failure to communicate, medication errors, charting by exception, and legal risks. Medication calculation errors can be one of three categories, conceptual, mathematical, and measurement, with conceptual errors (setup of the calculation equation) accounting for 68% of all errors . Nursing textbook publications teaching dose calculation often use multiple methods: ratio-proportion, “desired over have”, and various formulas to calculate medication dosage. Students then need to use the appropriate formula to solve the problem with fractions often leading to miscalculations with added or dropped zeroes. The use of dimensional analysis (DA) only requires the student to use a single equation, and learn one calculation process, rather than several steps required by other methods or even memorization of multiple formulas .