An analysis technique was developed on the basis of a modified version of Sudduth's niodel for calculating maximum packing fraction (MPF). Calculated MPF values were compared with experimental values obtained with rheological methods. By analysis of MPF data for three commercial titania powders dispersed in low molecular weight polyethylene, a large difference was observed between the experimental and calculated MPF values. For instance, a TiO2 P25/VF sample had an experimental MPF of 0.15 while the calculated value was similar to0.8. To address this issue, alpha was incorporated as a variable that would influence the packing fraction. By studying the behavior of three different types of submicron titania, an empirical equation was devised, that correlated a with particle size, particle size distribution, and packing structure. This overall treatment appeared to be relevant for predicting the alpha for binary millimeter steel powder mixtures. Thus, the form of this empirical function may guide us towards developing a derivation of a quantitative expression based on first principles.