SCREEN CAPACITY CALCULATIONThe biggest assumptions are the screen will have the correct rpm and stroke length for the given application. Also, there are some obvious errors in the published tables. Most manufacturers use a modified version of the VSMA (Vibrating Screen Manufactures. Association) formula to determine screen capacity. The twelve.how to know capacity for vibrating screen,Vibrating Screen Deck - Required Screening Area FormulaVibrating Screen Deck screening surfaces including Woven Wire Cloth, Woven Wire Mesh and Wear Resistant. How to determine required screening area. A separate calculation is required for each . Applies when open area of screening surface is less than the open area shown in the Factor "A" capacity chart. Factor "G" =.