This book offers an understanding of subjective well-being (SWB) in the Indian context across ages and strata. It discusses the conceptualization and measurement of both subjective well-being (SWB) and subjective ill-being (SIB) through a multi-phased research study. The structure of SWB and development, standardization, and indexing of an SWB Measure provide insights on how the SWB Measure can enable nations to find out the national level of SWB/SIB for its citizens. The index may be useful in identifying the level of people’s well-being or ill-being. It explores the possibility of implications and interventions in optimizing SWB both at the individual and collective levels. It is a consolidated account of the work done in SWB research, particularly with a cultural focus from the Indian context. This book has a wide application for students, researchers, psychometricians, practitioners, policymakers, and all individuals interested in concepts like SWB and Happiness.