Despite the significant attention that financial capability has received in the last 20 years, many of its aspects are poorly understood, and the term itself is ambiguously defined. Consequently, different measures of financial capability are used in empirical research creating a tendency to let the data dictate the conceptualization of the financial capability itself. This creates concerns about the reliability of the general findings for countries in Eastern Europe such as Poland. Therefore, the following study is carried out to address these limitations and contribute to the advancement of the literature on financial capability, first, by extending the mainstream of the theoretical work on financial capability with the conceptual proposition framed within Sen’s Capability Approach; second, by proposing the measurement model of financial capability; and third, by using data from the Polish household panel study, Social Diagnosis (SD), to identify factors which predict a positive change in consumer’s financial capability over time. Across these three aims, we found that higher income was a key predictor and substantially improved financial capability in Poland. We also showed the strong and positive link between financial capability and all included psychological variables. Our findings also highlighted the differential impact of demographic variables on financial capability. The findings of this study yield implications for scholars who would like to analyze financial capability in transition or developing countries, but are constrained by limited financial resources to create their own database or have no access to national financial capability studies.