To better understand the return on investment (ROI) from technical and vocational education and training (TVET) requires an overarching view. Hence, this Guide presents an analytic framework that summarizes some of the main elements and issues that need to be considered in measuring ROI. This includes establishing the scope, context and purpose for measuring ROI, adopting guiding principles, identifying costs, benefits and factors that impact on ROI, and approaches to data collection and analysis. The Guide then introduces a framework that looks at the ROI equation from a range of perspectives -- including economic and social dimensions -- and for different stakeholders, including individuals, businesses and societies. The Guide presents relevant ROI indicators and measures drawn from the existing international research. Finally, it provides guidelines to planning and collecting ROI data, along with a set of practical pro forma resources and case studies to assist the reader. The primary aims of this Guide are: (1) to identify the main issues and key elements to measure the ROI; (2) to present a framework that encompasses different stakeholder groups and identifies key ROI indicators; and (3) to provide fundamental guidelines and tools for ROI planning and data collection.