The differential equations describing heat and mass transfer during each stage of defrost are solved, and results are compared to measurement. Numerical solutions for defrost Stages I and II are obtained, while an analytical solution for Stage III is possible. For Stage I, the duration of the stage is predicted and validated by experiment. For Stage II, melt front and duration of the stage are predicted and in good agreement with measurement. For Stage III, the solution under predicts defrost time but generally simulating the general trends for duration seen in the experiments. We conclude with a graphical summary that indicates that further research is needed for measurements with greater super saturation and subcooling.