Techniques are presented for determining current levels based on the behavior of a charge pump system while driving a load under regulation. While driving the load under regulation, the number of pump clocks during a set interval is counted. This can be compared to a reference that can be obtained, for example, from the numbers of cycles needed to drive a known load current over an interval of the duration. By comparing the counts, the amount of current being drawn by the load can be determined. This technique can be applied to determining leakage from circuit elements, such as word lines in a non-volatile memory.