Our paper discusses questions of cultural fit in higher education from a cultural sociological perspective (Bourdieu, 1984). Firstly, we address the hinge function of subject-related cultural fit for successful studying. Building on a concept of operationalizing cultural fit using quantitative data (Brändle, 2019, 2021). To this end, we analyze data from the 21st Social Survey (Middendorff et al., 2017). We focus on the effects of subject-cultural and academic fit as cultural dimensions extended by social integration following Tinto (1975, 1993) on academic performance measured by (self-rated) average grades. The data show that the effect of study subject-related cultural fit on academic performance is mediated by social integration. Thus, our concept might help to improve sensitivity for educational inequalities and add to the discussion of increasing and widening participation in tertiary education.