The Comprehensive Source of Cathodic Protection Information
At DelWeg.Com you will find complete information about cathodic protection:

Interactive Online Design Tools for the CP Engineer

Tools to aid the corrosion engineer with design problems and/or just plain everyday computations are available on the WWW. Surely there are more items than are listed here, but this is a start. If you are aware of other tools which should be listed here, please let me know.

A large collection of calculators and interactive groundbed design programs have been made available by MESA at a site called CP Design Center . Included are interactive programs to design impressed current groundbeds, and to produce a galvanic anode design for protection of pipelines.

Electrochemical Devices, Inc. (EDI) has a nice design estimator on their website for their AT Linear Anode. This estimator helps with the design of an anode system to protect aboveground storage tanks. AT Linear Anode Estimator.

Several very good calculators are available On Loresco's website.
Vertical Resistance
Horizontal Resistance
Loresco Product Weight