This program is designed to compute statistical properties of gridded ASCII files from source datasets. The program was originally designed to process PRISM weather data (http://www.prism.oregonstate.edu/), however its scope has been expanded to be able to process most gridded ASCII files. Available statistical computations include minimum, maximum, delta, average, standard deviation. Mathematical operations include addition, subtraction, multiplicaton and division. Kelvin to Celsius (and Celsius to Kelvin) conversions are available. The output of a computation is another gridded ASCII file - each cell within the file representing the result of the calculation(s) used above. One may also extract individual grid cell values for any number of datasets using a point shapefile. Copy gc.exe to an empty directory and double-click on it. Run the setup program setup.exe. Open intro.html in Firefox/Internet Explorer or use GridCalc's help menu for instructions. Requires XP or Vista and .NET 2.0 or higher to run.