How to convert GPA to CGPA
Your CGPA is just a credit-weighted average of every semester GPA. For each semester multiply GPA × total credit hours to get the quality points, then divide the sum of all quality points by the sum of all credit hours.
Example: If Semester 1 GPA = 3.5 (18 credits) and Semester 2 GPA = 3.7 (18 credits), CGPA = (3.5×18 + 3.7×18) / 36 = 3.60.