The invention relates to a scale system which employs a microcomputer forming an integral part of the analog to digital conversion means in which the microcomputer controls the sequence of operations for performing the conversion, accumulates and stores digital data derived during the conversion of the analog signal and combines and processes that data to provide the digital output data resulting from the conversion, all in addition to performing other scale functions. The invention relates to an improved multicapacity weighing and computing digital scale in which switch means are provided to change the weight indication from pounds to kilograms and visa versa at any time either before or during a weighing operation. Provision is made to also convert all the weight limits and any stored tare weight. In addition, the unit price and total price or value display is either cleared or else converted from price per pound to price per kilogram and the total price recomputed.