Calculus is one of the most interesting fields of Mathematics yet difficult to pass. In this study, the common errors committed by the students were analyzed and categorized based on Newman’s error analysis guide. Using the quantitative research method, 10 Bachelor of Secondary Education major in Mathematics students enrolled in Calculus I and II were purposively chosen. The study hypothesized that no significant effects of the errors committed when classified according to types of errors and math fields to the overall performances in Calculus I and II of the students. Data collected were analyzed and interpreted using Mean Percentage Scores and Structural Equation Modelling. Based on the results, students commit errors mostly in differentiating functions involving logarithms. In terms of integration, students commit errors more on algebraic functions. Based on Newman’s error analysis, errors committed by mathematics major students are categorized into comprehension in both differentiation and integration processes. The result reveals that while students are equipped with the necessary skills needed for the transformation, process, and encoding, comprehension of the pre-requisite concepts should be strengthened and given attention specifically in algebraic and logarithmic functions. Finally, an instructional material addressing the identified common errors was developed.