Essential system operations calculations include: Perimeter, Area, Volume, Flow, Detention, Pressure, Head, Water Loss and Flow Estimator, Concentration, Dosage, Loading, Temp, Weight, Conversion, Horsepower and Efficiency, F/M Ratio, Sludge, Solids, Sewer Inflow Estimator, Chemical Calculations, and Common Conversions. The calculator also provides easy access to your state rural water resources and website.