The gross weight is one of the two constituent weights used to calculate the net weight. Interstate transportation rates are based on the “net” weight of the shipment, not its volume. The way the net weight is determined if for the tuck or truck and trailer to be weighed before the shipment is loaded or when it is unladen. This empty wight is called the tare weight. (From the French “tare”; literally meaning wastage in goods, deficiency, imperfection). When the shipment is loaded or when the vehicle is laden, a gross weight is obtained. The tare weight is subtracted from the gross weight which gives the net weight of the shipment. Arpin of RI has a huge truck scale at its facility in West Warwick that is calibrated twice a year by the State of RI.