Computer resource utilization modeling for multiple workloads includes a computer obtaining resource utilization data, the resource utilization data having groups of computer resource utilization measurements made during time intervals for a plurality of workloads. The computer determines parameters representing a distribution of the computer resource utilization measurements for each of the groups to generate a baseline of distributions across the time intervals for each of the plurality of workloads. The computer sums the baselines of distributions for the plurality of workloads to generate a combined baseline of distributions across the time intervals for a combination of the plurality of workloads.