Academic grading in the United States commonly takes on the form of five letter grades. Traditionally, the grades are A, B, C, D and F — A being the highest and F, denoting failure, the lowest. Numeric to letter grade conversions generally vary by school system and academic discipline. Grade point averages, standardized test scores and other alternative systems of measuring academic excellence can be used. A corresponds to great, B to good, a C is average, a D is minimal, and an F is a fail.