The immense demand for high performance computational resources has led to large increases in the energy consumption of data centers. Higher energy use tends to correlate with more waste heat being produced. This waste heat is often discarded, but it is a valuable resource that many data centers are starting to reuse for many different applications. In this paper we propose the Heat Reuse Factor (HRF) metric to quantify a data center’s heat reuse approach. We then propose and define the Green Supercomputing Ratio (GSR) metric to determine the efficiency of a facility based on the HRF value and the amount of CO \(_2\) emissions that are offset in accordance with green energy practices. Several examples of how to use the proposed metrics for varying heat reuse opportunities are covered using values for a Theoretical and a Practical data center. The resulting HRF and GSR values are provided to illustrate how HRF and GSR can be used to design more efficient data centers in the future.