Imperfections in conveyor belting and its supporting elements can adversely affect weighing accuracy of belt scales, particularly when weighing and/or metering low density materials, such as those encountered in the snack food industry. A system and methods for a belt conveyor according to an embodiment of the present invention provide simultaneous benefits of both short and long weigh spans. According to an embodiment of the present invention, a virtual weigh span may be programmably set to adjust for variations in the belt conveyor weighing system. Advantages include, higher degrees of accuracy and calibration to account for changes in the belt or belting system over time using non-mechanical adjustments. In addition, weight measurement error producing effects, some that may not be particularly known, may be reduced.