GPA equals the grade points earned, divided by credit hours attempted. Usually, this is broken down into a 4.0 grade point scale: 4.0 = A, 3.0 = B, 2.0 = C, 1.0 = D and 0.0= F. Courses are generally worth 3 credit hours for a core curriculum or required course, 1 credit for a lab course and 1/2 credit for physical education, music and other elective courses.
Example: Sally completes English 2, Spanish 1, Chemistry with a lab, and History. The credit hours applied are 3,3,3,1,and 3, respectively. She earns an A,C,B,B and B for the courses stated. To calculate, add total credit hours: 3+3+3+1+3= 13. Add the values of the grades: 12+6+9+3+9=39. Divide grade points by credit hours: 39 divided by 13 equals 3.0 or, a B average.