Illustrative embodiments estimate power consumption within a multi-core microprocessor chip. An authorized user selects a set of activities to be monitored. A value for each activity of the set of activities is stored in a separate counter of a set of counters, forming a set of stored values. The value comprises the count multiplied by a weight factor specific to the activity. The set of activities are grouped into subsets. The stored values corresponding to each activity in each subset are summed, forming a total value for each subset. The total value of each subset is multiplied by a factor corresponding to the subset, forming a scaled value for each subset. The scaled value of each subset is summed, forming a power usage value. A power manager adjusts the operational parameters of the unit based on a comparison of the power usage value to a threshold value.