AbstractThis work explores the optimum detergency conditions of alkyl ethoxylate (CXEOY) surfactants with the integrated free energy model (IFEM). IFEM is a molecular thermodynamic model that calculates the free energy of formation of oil‐swollen spherical micelles, with a core solubilization radius Ro, using surfactants from empty (oil‐free) micelles and oil molecules from a continuous oil phase. The described geometry allows for rapid calculations, using a personal laptop (3.4 GHz processor), where each solubilization energy profile (free energy vs. Ro curve) can be solved in 5 min or less. While previous work showed quantitative agreement between IFEM predictions and experimental solubilization of alkanes in CXEOY micelles, this work explores the possibility of using IFEM as a tool in surfactant selection. Experimental work has shown that detergency improved when operating near the phase inversion temperature (PIT) of the surfactant‐hexadecane system. The IFEM simulations in this work show, for the first time, that IFEM can be used to predict the PIT of surfactant‐oil systems, and that the surfactants selected via this method are consistent with the selection guided by experimental observations.