A large body of research has demonstrated that child benefit systems are of paramount importance in reducing child poverty, thus having an important vertical equity component. Although all child benefit systems embody in one way or the other such vertical equity objective, the primary objective of child benefit systems is to (at least partly) compensate for the costs associated with childrearing and to minimize the welfare loss relative to childless families, a horizontal equity objective. Most studies are concerned with vertical equity and child poverty reduction; here we also explicitly take the dimension of horizontal equity into account. In this paper, we propose and develop a two-dimensional framework for evaluating and classifying the outcomes of child benefit systems in terms of both vertical and horizontal equity. Treating these two objectives as analytically distinct permits the construction of a synthetic index of child benefit outcomes and allows for the explicit incorporation of a value judgement about the most important objective of child benefit systems. In doing so, we propose a novel measure for gauging horizontal equity based on the cost of children implicit in commonly used equivalence scales drawing on the public finance literature. We demonstrate the potential of our evaluative framework for policy purposes by means of an empirical application for 31 European welfare states. We contribute to the literature by highlighting the role of characteristics of benefit systems in achieving certain objectives regarding horizontal and/or vertical equity.Keywords Child benefit systems Á Horizontal equity Á Vertical equity Á Cost of children Á Child poverty Electronic supplementary material The online version of this article (