Method and arrangement for determining the remaining lifetime of a component of a power electronics appliance, such as a frequency converter, in which the lifetime data that is dependent on the ambient conditions and operation as specified by the manufacturer of the component is used, in which method at least one magnitude connected to ambient conditions, such as temperature, is determined, at least one loading magnitude of the component, such as speed of rotation, is determined and the calculation of the remaining lifetime is performed on the basis of at least one magnitude connected to ambient conditions, such as temperature, and of at least one loading magnitude of the component, such as speed of rotation, as well as of the lifetime data that is dependent on these ambient conditions and loading as specified by the manufacturer of the component.