To convert your college grades from one format to the other, use the calculator included below. Consult the particular school for an overview of what type of grades they give out: GPA, numerical or letters. To figure out your Grade Point Average, take into account the grades you got on tests, how many hours the class encompassed and how many credits it was worth. A 4.0 GPA (Grade Point Average) is a perfect A+ score. For example, a 3.4 GPA would equal a ‘B’ score.