BackgroundCannabis demand (i.e., relative value) is usually assessed as a trait-level risk-factor for cannabis use and consequences. This study examined within-person variability in day-level intensity (i.e., amount consumed at zero cost) and Omax (i.e., maximum cannabis expenditure) and tested hypotheses that demand would be positively associated with day-level cannabis use. MethodsYoung adults (n=85) reporting past-month simultaneous alcohol and cannabis use completed two daily surveys for 30 days. Morning surveys assessed prior-day cannabis use and evening surveys assessed day-level demand (i.e., intensity, Omax). Multilevel models tested day-level effects of intensity and Omax on any cannabis use and flower use frequency and quantity (i.e., grams). ResultsApproximately 52 % and 46 % of variability in intensity and Omax, respectively, was due to within-person change. At the day-level, higher intensity and Omax were associated with higher likelihood of any cannabis use, regardless of formulation; Omax was associated with use of flower in particular; and intensity was associated with the highest quantity of use. At the person-level, only Omax was associated with flower use likelihood, and only intensity was associated with flower quantity across days. ConclusionsCannabis demand demonstrated day-to-day variability, conceivably in response to various internal states and external factors. Intensity and Omax were related to elevated likelihood of using any cannabis, particularly flower, at the day-level. Overall, these data illustrate the validity and utility of brief cannabis demand measures, which might be used to further understand cannabis’ reinforcing value at a fine-grained level.