Change each letter grade to the number of grade points it is worth for your GPA. Most U.S. schools use a four-point system where an A equals 4 points and each lower grade is worth one less point. Some U.S. schools also use pluses and minuses, such as an A- or a B+. Typically, a plus adds 0.33 to your point value while a minus takes away 0.33, making an A- equal 3.67 and a B+ equal 3.33.
Multiply the grade points by the hours for which the class counts on your transcript. For example, if a class is a two-credit class and you got an A-, multiply 2 by 3.67 to get 7.34 total grade points for the entire class.
Add up the total grade points per class for all of your classes.
Add up the total credit hours earned for all your classes. This total will usually be displayed on your transcript.
Divide your grade points earned by your credit hours earned to find your GPA. For example, if you earned a total of 382 grade points for 120 credits taken, divide 382 by 120 to find your GPA equals 3.18.