Although the heavy episodic drinking (HED) measure of 5+ drinks (sometimes 4+ for women) is used extensively, there is no empirical basis for the designation of 5 drinks as the threshold (vs. another threshold that may perform equally). The present study sought to determine the threshold for HED that maximally predicts proximal and distal adverse-drinking-related outcomes. Participants included 115 young adults (57% female; 96% Caucasian) who partook in an 8-week Internet survey that assessed daily drinking as well as next-day hangover; 10 months later, adverse outcomes (problem drinking, alcohol-related problems, maximum number of drinks, and drug use) were surveyed. Thresholds were computed, with a range from 1+ drinks to 15+ drinks, and outcomes were predicted from each threshold. Findings for hangover measures showed relatively good convergence across multiple indicators, with greatest prediction occurring at a threshold of 10+ drinks per occasion. Different thresholds were observed for long-term outcomes, with higher thresholds indicative of outcomes with greater severity. Although alternatives to HED, such as subjective effects and blood alcohol concentration, can indicate risky drinking, a threshold measure of HED may have advantages in terms of prevention and of intervention efforts.(PsycINFO Database Record (c) 2016 APA, all rights reserved)