Colleges compute student's GPAs in order to rank the performance of students in each graduating class. The GPA takes into consideration all of the classes that you have taken and weighs them according to how many credits each class was worth. Your GPA will be looked at by employers, graduate schools and to determine if you will graduate with honours. To calculate your GPA, you need to know all of your grades and how many credit hours each class was worth.

Request your transcript from the registrar's office at the university. The transcript will have all of your grades as well as how many credits each class you took was worth.

Refer to the university's handbook to find the GPA scale used by your university. Most universities offer four points for an A, three for a B, two for a C, one for a D and zero for an F. Most also add 0.33 points if you have a plus and subtract 0.33 points if you have a minus, except for A+ grades, which are usually still awarded four points.

Convert each of your grades to the point value using the GPA scale of your school. For example, using the four point scale, if you had one A, two B+'s and a C, you would convert those to one 4, two 3.33s and a 2.

Multiply the point value of your grades by the number of credit hours each class was worth. For example, if the class you got an A in was worth four credits, you would multiply four times four to get 16. If the first B+ was worth two credits, you would multiply 3.33 by two to get 6.66. If your remaining B+ and the C were worth three credits each, you would multiply 3.33 by three to get 9.99 and two times three to get six.

Add the weighted value of each class. Continuing this example, you would add 16 plus 6.66 plus 9.99 plus 6 to get a total of 38.65.

Total the number of credit hours of all your classes. In this example, you would add four plus two plus three plus three to get 12.

Divide your total points by your total credit hours to calculate your GPA. Concluding this example, you would divide 38.65 by 12 to find your GPA would be 3.22.