Several developments in the measurement of justice have drawn on Amartya Sen’s work on capabilities. This article addresses the relationship between Sen’s theoretical work and its interpretation in the measurement of justice, in particular by the United Nations Development Project (UNDP) and by the British Equality and Human Rights Commission and Government Equalities Office in its Equality Measurement Framework. It starts with a review of the diverse interpretations of Sen’s work, which range from considering it to be an innovative radical development to locating his work within the liberal tradition. Central to the article is the question of whether it is possible to develop a meaningful operationalization of Sen’s philosophical distinctions, in particular that between capabilities and functionings, so as to inform measurement frameworks. It finds that on both conceptual and methodological grounds it is not possible to sustain this distinction in practice. This is illustrated by an analysis of the changing measurement of justice in frameworks developed by the UNDP and the UK government. Changes in the content of the measurement frameworks in radical or neoliberal directions are not constrained by Sen’s theoretical analysis, despite claims that Sen’s work informs these frameworks. The openness of Sen’s work means that it can be used by forces generated by the neoliberal environment to support their redefinition of justice.