Enter the total square footage, minutes, and thickness in mils into the calculator to determine the anodizing amperage.

Anodizing Amperage Formula

The following equation is used to calculate the Anodizing Amperage.

AA = (720*SF)/T * Mils

  • Where AA is the anodizing amperage
  • SF is the square footage
  • T is the time (minutes)
  • mils is the thickness (1mil = .001″)

This formula is known as the 720 rule for anodizing.

What is Anodizing Amperage?


Anodizing is the process of using electric current to pass through a newly manufactured aluminum, titanium or other metal object. This process causes a chemical reaction that creates a uniform coating on the outside of the object. The color of the coating depends on the type of metal and its thickness.

The term “anodizing” comes from “anode,” which is an electrode in an electrolytic solution. In anodic oxidation, aluminum becomes the anode and oxygen and electrons become cathodes. The process forms a barrier layer that protects the object being anodized from corrosion, wear or damage.

The anodizing process also toughens the metal, making it more durable than non-anodized aluminum.

The anodizing amperage is simply the correct amount of current needed to achieve a proper anodizing.