This article describes the development of the Clinical Load Index (CLI), a new metric for accurately describing and comparing staffing levels across college and university counseling centers. The CLI was developed by the Center for Collegiate Mental Health (CCMH) with support from the Association for University and College Counseling Center Directors (AUCCCD) and the International Accreditation of Counseling Services, Inc. (IACS). Historical approaches to measuring staffing levels are reviewed alongside the design principles used to develop the CLI. Data collection methods, resulting CLI distributions from four academic years (2017-2018, 2018-2019, 2020-2021, and 2021-2022), and research findings using the CLI are reviewed. Implications for staffing college and university counseling centers are reviewed.