In a method of operating a washing machine, different values for the power required by a drive motor of a drum of the washing machine to accelerate the drum from 30 rpm to 80 rpm are measured and stored as reference values. They can be differentiated by weight or load of laundry, potentially also by different types of laundry. These values are then compared to values derived from an actual washing or dry-spinning process, respectively. As a result of this comparison, it can be determined which values actually measured correspond sufficiently to stored values, and then the load can be determined from this result.