Percent of sales growth:

The percent growth method, too is based on opinions, with past data serving as a bench-mark.

So the sales forecast for the coming year are set at the same figure for the current years actual sales or by adding a set % to last years sales.

            Next years sales = This years sales          X         This years sales

                                                                        Last years sales

                                    YI        Yo        Y2        =          S2         = So     X         So

                                                                                                                        S1

                                    SI         So        S2

The assumption here is that this years sales are inevitably related to last years while next years are related to this years sales.