This document reviews literature on conceptualizing and measuring family wellbeing. It finds that while family wellbeing is widely discussed, there is no consensus on how to define or measure it. The review examines theoretical models of family wellbeing and approaches to measurement. It concludes that comprehensive, longitudinal data is needed to understand family wellbeing and the impact of policies, but such data is currently lacking in the UK. Representing both objective and subjective dimensions across multiple domains would ideally capture how various factors interact to influence family functioning over time.