In the combined stage sintering model previously introduced[l], a single equation was derived that quantifies sintering as a continuous phenomenon from beginning to end. The microstructure is characterized by two separate parameters representing the geometry (Γ) and the scale (G). Calculations of Γ from experimental data show the effect of surface diffusion and microstructural geometry on Γ. The model is reviewed and discussed with respect to the sintering of alumina and spherical nickel powder.