Abstract: A system and methods for calculating at least one unknown metabolic flux of a plurality of cells. In one embodiment, the method includes the steps of constructing a metabolic network having a plurality of reaction components, the reaction components representing at least glycolysis, reduction of pyruvate to lactate, TCA cycle, and oxidative phosphorylation, measuring at least two metabolic rates of a plurality of cells corresponding to at least two of the metabolic network reactions, and calculating metabolic fluxes of a plurality of cells for the rest of the metabolic network reactions from at least two measured metabolic rates of a plurality of cells corresponding to at least two of the reactions.