This project aimed to quantitatively measure the ability of first year science students to transfer their mathematical skills and knowledge to a physical context. An instrument used in earlier studies to measure transfer of mathematical knowledge was modified for this project, and tested with 49 student volunteers. This paper presents the Transfer Index, a novel way of measuring the degree of transfer of the students' mathematics skills and knowledge. It is demonstrated that the Transfer Index is a useful way of quantifying transfer and that it has predictive validity in a natural educational setting. (Contains 7 tables, 4 figures and 5 footnotes.)