Star-polymers with arm numbers ranging from 3 to 10 have been synthesized and characterized by conventional GPC and GPC-light-scattering. The GPC elution behavior of the stars was studied and compared with predictions from computer simulations. The comparison of simulated and experimental data shows reasonable agreement if the arms are sufficiently long. Thus, using computer simulations GPC calibration curves of non-linear topologies can be constructed based on the calibration curve of the corresponding linear polymer. For star polymers prepared by atom transfer radical polymerization we found additional peaks having twice the molecular weight of the peak that has been assigned to the star. The elution volumes of these peaks were in good agreement with an expected dumbbell topology that would arise from coupling of the arms of different stars.