Impressed current cathodic protection of aboveground storage tanks usually considers the use of flexible wire anodes set in a concentric-loop arrange and placed within a sand cushion below the tank’s bottom. A main variable for any cathodic protection system is its electrical circuit resistance in order to estimate the power requirements; since experience has shown that the existing analytic methods for calculating this parameter are not always as accurate as desired it may be common to obtain significant differences between the calculated value and the one measured on field this paper presents a comparative study of different cases in which impressed current cathodic protection systems employing this type of anodes were designed installed and evaluated through several analytic methods which later were compared with values obtain on the field by different techniques; the collection of results in both office and field was evaluated and related in order to observe the resistance behavior for a single anode loop and for the entire system according to critical construction features including the dimensions of the tank and sand conditions allowing to find the most effective calculation method of the system’s electrical resistance in each case.