The equations derived from modern filtration theory for compressible cake filtration at apparently constant pressure have been programmed into a conventional computer spreadsheet package. Simulations were then performed, including investigations of the effect of increasing the slurry concentration before filtering, and the distribution of pressure between the filter medium and the cake with increasing filtration time. When the medium resistance is finite the pressure drop across the cake is not constant and, consequently, the cake concentration and specific resistance are functions of time, and must be iteratively deduced. The cell formulas for the computer spreadsheet are provided, together with example outputs from demonstration simulations.