This paper presents the conversion parameter values of the magnetic properties of magnetic fluids. These
values were determined for three magnetic fluid samples containing particles with diameters between 30 Å and 170 Å. The factors that may affect the value of this parameter (size of particle, magnetic properties, the presence of clusters and aggregates) are also studied. The determined values for the conversion parameter (γ) are between 0.25 and 0.76 and the determined limit value is 0.8. Because many applications require magnetic fluids with the saturation magnetization as high as possible and the viscosity as low as possible [1], it has been considered necessary to determine this parameter which describes the quality of magnetic fluids.