An apparatus is configured to calculate consumption power of a processor caused by execution of a program, based on sampling data acquired by event-based sampling. The apparatus determines whether the processor is in an idle state, by using the sampling data of a clock event, where the clock event is an event which generates an interrupt at fixed time intervals when the processor is not in the idle state, and which generates the interrupt when a state of the processor changes from the idle state to a non-idle state. In a case where the processor is in the idle state, the apparatus calculates a first amount of consumption power of the processor in the idle state, based on a second amount of consumption power calculated using a consumption power model and a third amount of consumption power included in the sampling data.