Ball's formula method is a classical method used in the thermal processing industry, the basis and the precursor of a number of most recent methodologies. It has received a lot of attention, being reviewed, criticized, compared and evaluated by several investigators. The use of Ball's method relies on appropriate diagrams which sometimes are difficult to use, find or reproduce. After presenting the principles involved in the development of Ball's formula method, reviewing the literature related to that particular method, and discussing its limitations, some working, regression equations developed in order to facilitate the application and the use of the method are presented.