With the unprecedented impacts of the COVID-19 outbreak, higher education institutions have faced a number of challenges, one of which is the transition to online education. University students have experienced varying levels of stress as the largest group affected by this transition. The perceived level of academic stress experienced by university students in this new system has become significant for the improvement in online learning at the tertiary level. Therefore, this study aimed to measure the level of academic stress among university students including the components of pressures to perform, perceptions of workload, academic self-perceptions, and time restraints during online learning. In order to measure the level of academic stress among university students, a quantitative research design was adopted through gathering statistical data from 147 undergraduate students studying online in different departments in Turkey utilizing “The Perception of Academic Stress Scale” including the components of pressures to perform, perceptions of workload, academic self-perceptions, and time restraints during online learning. The results of this quantitatively designed study revealed that the perceived level of academic stress among university students was found as neutral in general; regarding the components of "Pressures to Perform" as high, of “Perceptions of Workload”, "Academic Self-Perceptions" and "Time Restraints" as neutral. Some statistically significant differences were also detected in the perceived level of academic stress in relation to the variables of gender, age (Gen X vs Gen Y), year of study, satisfaction with the learning and home environments.