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This study aims to compare the permeability coefficients calculated based on the particle size analyses peculiar to the soil samples of some districts at Meşelik and Tepebaşı residential areas in Eskişehir. The study area covers 6 km2. In this study, the properties ofunits in alluvial deposit cut by 29 boreholes previously drilled in the area were examined from borehole logs contained in the geological reports. On the basis of the sieve analyses, particle size distribution curves were drawn. The parameters of D60, D50, D30, D20, D10, I0, U, Cc values were calculated by using these graphs. Porosity values werecalculated by using Gs, specific density and water content. Permeability coefficients were also calculated for the units having no water content values considering the intervals accepted by the literature. Dependently or independently on porosity values, permeability coefficients were individually calculated by using the Hazen, Kozeny-Carman, Breyer, Slichter, Terzaghi, USBR and Alyamani-Sen formulas, for each core samples from different depths of the boreholes and then the most appropriate formula for different depths and units was determined. Variations of permeability coefficient for different grain sizes and porosities were studied. Based on the outcomes of this study, calculated permeability coefficients are almost similar for uniform soil units, however, different for non-uniform units. It is inferred that using above-mentioned approaches for estimation of permeability coefficient for clay material is not suitable. As a conclusion, estimation of permeability coefficient using Breyer, Slitcher, Terzaghi and Alyamani-Sen approaches are more suitable for non-uniform units while Hazen, Cozeny-Carman ve USBR are applicable for uniform units. [ABSTRACT FROM AUTHOR]