A charging factor is determined applicable to each time interval in a period of time during which at least one data transfer was conducted. An amount of data transferred during each time interval is determined. A total charge applicable to the at least one data transfer is computed based at least in part on the charging factor applicable to each time interval and the amount of data transferred. Alternatively or additionally, a plurality of potential start times and an amount of data for a data transfer are identified. A set of time intervals associated with each of the potential start times are determined. For each of the potential start times, an estimated charge applicable to the data transfer is computed based at least in part on a charging factor applicable to each of one or more time intervals associated with the potential start time and the amount of data estimated to be transferred.