This paper investigates the role played by self-confidence in college applications. After documenting how much gender and social differences in self-confidence explain inequalities in access to college, we show that correcting underconfidence helps to close the gap in college applications. We collect unique data on student self-confidence using experiments on more than 2,000 French college applicants. We match this data with administrative data on real college applications. After measuring student under- (or over-) confidence in their academic abilities, we randomly corrected miscalibrated beliefs about relative academic ability by providing some students information on their real rank in the grade distribution. Our results show that the best female students and the best students from low socio-economic status systematically underestimate their rank in the grade distribution. As a result, they apply to less selective programs. Providing information on the correct position in the grade distribution made the best students apply to more ambitious programs with stronger effects for female and low-SES students.