While countries and institutions use a range of alpha-numerical grading scales, their formulas for calculating a student's cumulative grade point average (CGPA) score are basically the same. In mathematical terms, the CGPA score is a "weighted mean," wherein the influence each grade has on the cumulative score depends on the number of credit hours the course was worth. Additionally, courses audited or taken on a "Pass/Fail" basis are omitted from the CGPA calculations completely.
Locate the letter-to-point conversion table on your transcript. For example, A = 4.0 at an American university while A = 12 at the University of Windsor, in Ontario. If you cannot find this table, visit the website for your Registrar's Office.
Count all of the courses for which you received a letter grade. Do not include courses in this tally that were audited, taken as "Pass/Fail," incomplete or dropped.
Add together the credit hours for all of the courses from step 2. For example, if you took a total of 15 three-credit-hour courses and 17 four-credit-hour courses, you would multiply 15 by 3 (45 credit hours) and 17 by 4 (68 credit hours). This would give you a grand total of 113 credit hours.
For each letter grade on your transcript, multiply the grade's numerical point value (from step 1) by that course's credit hours.
Add together all of the point-hour products from step 4.
Divide the total from step 5 by the result from step 3. This will give you the raw CGPA score.
Round your raw CGPA score to the nearest hundredth to calculate your actual CGPA score. For example, 3.477 would be rounded to 3.48.