The Porosity Calculator is a computer application written to satisfy a need at the State of Alaska Division of Oil and Gas. The calculator was created in Visual Basic.NET and averages porosity from thin section photomicrographs. It finds the porosity by determining the percentage of a selected value of blue for the whole photo or a user defined area within the image. The calculator has a QC function that displays the areas on the image selected as pore space, in order to more accurately determine true producible pore space. It includes a measurement tool that can be used to measure pore widths. It also records the metadata involved in the calculation of the porosity and widths measured in an access database.