Abstract: A system and method of optimizing water cooling system energy efficiency, including a monitoring device to receive heat data corresponding to heat energy of a unit of water associated with a recirculating water system, power data corresponding to power being applied to the system, and load data corresponding to a load associated with the system. The monitoring device determines a measured metric by calculating a measured rate of water traversing the recirculating water system based on the heat data and determining a ratio of the power data and the measured rate of water. The monitoring device determines an efficiency metric of the system by comparing the load data to a look-up table and, based thereon, calculates a key performance indicator of the recirculating water system as a ratio of the efficiency metric and the measured metric, which is output to a graphical user interface.