Change your grades from letters to numeric values. An "A" equals four; a "B" equals three; a "C" equals two and a "D" equals one. An "F" equals zero. If you have a "+," add 0.33 to the grade. If you have a "-," then subtract 0.34 from your grade.
Multiply your numeric grade by the number of credit hours your course was worth. This is the quality points you earned for the class.
Add together your total number of credits.
Add together your quality points for each class.
Divide your total quality points by the total number of credits taken to calculate GPA.