There are a number of ways that student investment can be measured, including full cost of attendance (COA, also known as sticker price), net price (COA minus grant aid), and opportunity costs in the form of forgone earnings. This paper explores those options and makes recommendations for how student investment should be measured with ideal data and with data that are currently available, including U.S. Department of Education (ED) data that are available for all colleges and nonpublic data that institutions may be able to access for their own students. The recommendations in this paper are based on an extensive review of research and analyses of publicly available data, as well as discussion with staff members at the Institute for Higher Education Policy (IHEP), the Bill & Melinda Gates Foundation, and members of the Postsecondary Value Commission Research Task Force. The paper also identifies issues that require more research and includes recommendations for improving publicly available data to allow colleges and policymakers to better measure student investment.