Unequal financial outcomes often originate from unequal chances. Yet, compared to outcomes, little is known about how individuals perceive unequal distributions of chances. We investigate empirically the role of different sources of unequal chances in shaping perceptions of inequality. Importantly, we do so from an ex ante perspective — i.e., before the chances are realized — which has rarely been explored. In an online survey, we asked uninvolved respondents to evaluate ex ante the fairness of unequal allocations of chances. We varied the source of inequality of chances, using a comprehensive range of factors which resemble several real world situations. Respondents also evaluated how much control individuals hold over the distribution of chances. Results show that the source of inequality has considerable effects on the ex ante perception of fairness and control. Unequal chances based on socioeconomic and biological factors, such as gender, family income and ethnicity, are evaluated to be both unfair and beyond one’s control. Allocations based on factors judged to be under higher individual control, such as effort and knowledge, are perceived as fairer. Luck is the exception, ranking as high in fairness as effort and knowledge, but similarly low in individual control as ethnicity, family income, and gender.