The invention relates to a method and to a device for the contactless measurement of a mass flow or volumetric flow of an electrically conductive fluid by means of Lorentz force compensation. The aim is achieved according to the invention by means of a method for the contactless measurement of the mass flow or volumetric flow (v1) of an electrically conductive fluid, wherein a magnetic field is generated at the location of the flow and a Lorentz force arising due to the relative motion between the magnetic field and the mass flow or volumetric flow (v1) is detected, wherein a second known flow rate of an additional electrically conductive fluid (v2) or of a moving electrically conductive solid (4, 5) of known velocity is superposed on the mass flow or volumetric flow (v1) in the magnetic field and the flow rate of the fluid to be measured is determined from the thus known velocity and the measured Lorentz force, and by means of a device for the contactless velocity measurement of the mass flow or volumetric f
