An information processing apparatus comprises an acquisition unit configured to acquire information according to the usage circumstances of the portable electric generator; an estimation unit configured to estimate a type of an electrical device that is connected, based on a measurement result with respect to a voltage and a current when the portable electric generator supplied electric power that is included in the information according to the usage circumstances; and a calculation unit configured to calculate a rental fee associated with an electric power amount supplied by the portable electric generator at the rental destination, using a billing coefficient corresponding to an electrical device estimated by the estimation unit, and the measurement result.