University makerspaces have been touted as a possible avenue for improving student learning, engagement, retention, and creativity. As their popularity has increased world-wide, so has the amount of research investigating their establishment, management, and uses. However, there have been very few studies that use empirical data to evaluate how these spaces are impacting the people using them. This study of three university makerspaces measures engineering design self-efficacy and how it is correlated with involvement in the makerspaces, along with student demographic factors. The three university makerspaces include a relatively new makerspace at a Hispanic-serving university in the southwestern US, makerspaces at an eastern liberal arts university with an engineering program that has been created within the last decade, and a makerspace at a large, research university in the southeast often considered to be one of the top programs in the nation. Students at all three universities are surveyed to determine their involvement in their university's makerspace and how they perceive their own abilities in engineering design. The findings presented in this paper show a positive correlation between engineering design self-efficacy and involvement in academic makerspaces. Furthermore, correlations are also seen between certain demographic factors and the percentage of students who choose to use the academic makerspace available to them. These findings provide crucial empirical evidence to the community on the self-efficacy of students who use makerspaces and provide support for universities to continue making these spaces available to their students.