Distributed computing task costing is disclosed. Costing can be employed to determine if a task will be passed to a distributed computing cluster including mobile devices. Costing can include determining a base cost value predicated on a selectable level of utility to a user of a burdened device, a base time value related to completing the task without the use of the cluster, determining a delay cost, and any monetary costs associated with performing the task without the use of the cluster. Costing can further include demining a relief cost that can include the selectable level of utility, a relief time value related to completing the task with the cluster, the delay cost, an incentive cost based on the sum across a set of relief devices and their corresponding parameters for cluster participation, and any remaining monetary costs borne by the burdened device. Where the base cost value and relief cost value satisfies conditions, a task can be divided into subtasks that can be distributed to the cluster to accomplish the task in a distributed computing environment.