Excessive alcohol consumption is a major concern. Alcohol consumption data are typically collected via self-report questionnaires. However, research has suggested that individuals are unable to identify a standard drink size and that their self-report may be influenced by certain environmental conditions, calling into question the reliability and validity of self-report. The free-pour is an objective measure that may provide a clearer picture of current alcohol consumption trends, individuals’ knowledge of standard drink sizes, and accuracy of self-report. This systematic review of existing free-pour assessment methods suggests that individuals are unable to identify and pour standard drink sizes, with the largest discrepancies occurring for liquor and wine pours and pours into larger and wider glasses. Additional variables that appear to influence pouring behavior are gender, pouring location (e.g., home or laboratory), pouring task (e.g., selecting a line or physically pouring), and drinking history; however, additional research is necessary to better understand the effects of these variables on pouring behavior. These findings have important implications for the accuracy of self-report measures, as well as clinical implications for alcohol use screenings, alcohol education courses, and brief interventions for alcohol use. The systematic review concludes with recommendations for practical applications and future research of the free-pour assessment.