In rotating packed beds (RPBs) centrifugal forces are exploited in order to intensify the mass transfer between different phases. In order to derive correlations describing the hydrodynamics and the mass transfer in RPBs and to improve the understanding of fundamentals, comprehensive and systematic experimental investigations are required. The present study focuses on the dry pressure drop that was investigated for different packing materials and rotor dimensions. The pressure drop induced by rotation, defined as centrifugal head, mainly depends on the outer diameter of the rotor. The frictional pressure drop in the packed bed depends on the rotor dimensions and the packing properties as well as on the operating conditions. Existing correlations do not predict the pressure drop accurately; thus, a modified correlation basing on the extended channel model is proposed, estimating the dry pressure drop in RPBs with deviations below +/- 15% for knit meshes and metal foams for rotors with outer packing diameters of 0.36 and 0.56 m.