ABSTRACT While there is little discernible difference between girls and boys in maths competence during secondary education, on average, girls have lower confidence in their maths skills. Over time, this difference leads to gendered choices of education and occupation. Research explaining the maths confidence gap focusses on psychological factors and socialisation into stereotypical gender roles. However, how the peer context shapes the self-perception of competence and how this self-image affects social integration and popularity of girls and boys is barely understood. We analyse friendship networks and perceptions of maths confidence in Sweden and Germany to answer these questions using the CILS4EU dataset ( N = 7,472) and multi-level, longitudinal network models. We find that maths confidence of girls accurately follows their maths grades and social relations have little impact on girls’ self-evaluation. Boys tend to overestimate their ability and are more susceptible to peer processes; social comparison processes inform boys’ maths confidence. This suggests that math ability is important for boys but socially irrelevant for girls. Concerning friendship choices, we find that boys and girls with higher maths confidence are often more integrated. Thus, we do not find social pressure on girls to adhere to gendered math-stereotypes – the opposite is the case.