This book explores modern approaches to sustainability and its measurement. It thoroughly reviews a wide range of existing sustainability measurement systems. Accordingly, the book documents the state of progress toward sustainability measurement by first assessing the past development of wellbeing measurement going beyond GDP and synthesizing the various conceptual approaches to sustainability and its dimensions. It then explores crucial methodological aspects that stay at the core of constructing a sound index system. In the main part of the book, we map the available indices or index systems, their conceptual and methodological backgrounds as well as approaches, which have not yet resulted in an index, but have the potential to contribute to a better understanding of sustainability. More specifically, the book assesses the scope, motivation, and potential usage of each index. It also documents their limitations and drawbacks. This mapping exercise is useful for policymakers, researchers, and practitioners as it offers a detailed and compact overview of where we are and what we still need to account for when measuring sustainability.