In recent years, internationalAlarcón-García, Gloria institutions such as the OECD, the UN and the European Commission have called for the development of well-being-oriented budgetary frameworks as a means to ensure more inclusive, equitable, and evidence-based public policymaking. This chapter responds to that call by offering a novel contribution to feminist economics: a gender-sensitive budgetary approach grounded in a multidimensional understanding of well-being. The work is highly innovative in multiple respects. First, it proposes a budgetary indicator that goes beyond GDP, integrating both the Capability Approach (CA) and Subjective Well-Being (SWB)—two paradigms that have traditionally evolved separately and are often considered theoretically antithetical. Second, it brings visibility to public infrastructure expenditures as a critical, yet underexplored, dimension of gender budgeting. And third, it operationalizes a gendered well-being indicator aligned with recent OECD proposals for feminist and well-being-oriented public finance. The chapter introduces the Well-being and Infrastructure by Gender Index (WIGI), a composite indicator designed by the author to assess the differentiated effects of infrastructure investments on the capabilities and subjective well-being of women and men. Based on disaggregated budget data, service typologies, and lived experiences, the index enables an intersectional evaluation of how public infrastructure either enhances or restricts real opportunities for individuals, depending on their sex and social position. In doing so, the chapter challenges the presumed universality and neutrality of infrastructure spending—showing that infrastructure is neither neutral nor equally used and beneficial to all citizens, especially from a gender perspective. The work is grounded in feminist economics but also contributes to expanding its methodological frontiers by integrating empirical tools and evaluative criteria that link macro-level budget decisions with micro-level well-being outcomes. The chapter argues that this intersection—between budgetary planning and multidimensional gendered well-being—opens a path for more just and effective public investment strategies. This is particularly relevant in the current context of post-pandemic recovery, ecological transition, and renewed debates on care infrastructure. By positioning infrastructure within the framework of SDG5 (Gender Equality) and SDG9 (Infrastructure, Industry and Innovation), the chapter contributes to rethinking how public finance can be mobilized to advance substantive gender equality and territorial equity.