Growing demand for the solid state meters for power and energy measurement leads to the fully integrated Hall sensor based microsystem solutions. In this paper we describe fully integrated SOI Hall sensor based microsystem for power and energy measurements with dynamic offset cancellation. Since Hall sensor behaves like a natural four quadrant multiplier it is used to multiply the line voltage and current giving the output voltage proportional to the instantaneous power. Furthermore, voltage at the Hall output is proportional to the line active power and can be further processed. By converting the sensor output voltage to digital signal using a sigma-delta demodulator followed by a digital filtering, the energy consumption is observed at the end of the processing chain. The entire microsystem has been designed for high linearity and resolution, and integrated in 0.5 mu m FD SOI process.