The present invention is directed to an apparatus and method for measuring the weight of material such as rock, earth, wood, pulp, grain, gravel, sand, ore, cement etc. being processed or moved by an apparatus such as a conveyor, apron conveyor or bucket elevator driven by an electrical motor. The apparatus measures the electrical energy consumed by the motor powering the apparatus during operation of the apparatus and uses a calibration formula derived from an average of no-load readings plus up to 2.0 standard deviations for converting the power consumption of the motor to tonnage per hour of raw material processed by the apparatus. A continual record is kept of all "No-load" and "start-up load" time during the recording process and these figures are totalized along with tonnage for the recording period.