text: how do you calculate a college gpa?   take the grade in each class and find its gpa a = 4.0 b+ = 3.5 b = 3.0 c+ = 2.5 c = 2.0 d = 1.0 then multiply that number by the credit hours.  3 credits of an a would be 4 x 3 = 12.  do this for each class you have taken and then add up the points.  then divide the points you have by the total number of credits.