Two types of culture bags are typically used. Among the criteria for evaluating the bioreactor performance, mixing time and shear stress are important indicators. Experiments and numerical analyses are conducted to evaluate and predict the performance of an orbital shaken bioreactor by analyzing mixing time and shear stress. Reliability is ensured by performing numerical analysis under the same conditions using FLUENT. The error between the experimental and numerical analysis results is within the error range of the experiments. For two different working fluid volumes the mixing time and shear stress are predicted using validated numerical models.