Mass balances are an effective method for evaluating the reliability of experimental test data obtained from coal preparation plants. Although conceptually very simple, the mathematics associated with this procedure can be overwhelming when conflicting data sets or complex circuits are evaluated. Fortunately, modern spreadsheet programs now include powerful minimization routines that can be readily adapted to solve common mass balance problems. This article reviews the mass balance problem and describes how embedded spreadsheet tools can be used to reconcile conflicting data. An example problem involving the evaluation of data from a spiral-flotation circuit is presented to illustrate the inherent simplicity of this new approach to solving mass balance problems.