A method, system and program product for determining a cost differential resulting from a migration of computational workloads between computer platforms is disclosed herein. Information regarding current and planned hardware and software use on the computer platforms and the costs associated therewith is provided and supplemented with model data including historical data and industry averages. A cost and capacity measurement associated with the current and planned use and cost is derived. A required processing capacity migration between platforms is determined for a proposed computational workload migration therebetween and a resultant cost and capacity measurement is calculated for each platform to determine the resultant cost differential.