AbstractThe hydrodynamic characterization of bioreactors is an integral element in the industrial development of cell and gene therapy platforms where mild process conditions with low power inputs are desired. In this technology, modular single‐use equipment is frequently used for which accurate techniques to measure or predict scaling parameters, such as power input, are of high interest. In this work, computational fluid dynamics as well as two experimental approaches are used to determine the power input in a small‐scale bioreactor and validate the employed techniques. Particular attention is given to the implications arising from low‐speed operation with low power input conditions.