Once all the 14 GSCs have been answered, they should be tabulated using the IFPUG Value Adjustment Equation (VAF)

Another way to understand the formula is VAF = (65 + TDI)/100, where TDI is the sum of the results from each question. A Microsoft Excel formula would be: =0.65+SUM(A1:A14)/100 ; assuming that the values for the characteristics were in cells A1 – A14.