A system and method of measuring power consumption in an appliance is provided. An electrical characteristic of a power signal, such as a voltage component and/or a current component, can be detected at the appliance. The detected electrical characteristic can be processed using a signal processor. During signal processing, the detected electrical characteristic can be shifted based on a predetermined threshold and converted to a digital signal. An electrical characteristic offset can be determined based on an average electrical characteristic value of a plurality of detected electrical characteristics. The difference between the electrical characteristic offset value and an instantaneously detected electrical characteristic value can be used to determine power consumption of the appliance.