Here's how it works:
* Contact Hours: Each subject is assigned a specific number of contact hours per week (e.g., 3 hours per week for a theory subject, 2 hours for a lab).
* Credit Points: These contact hours are then converted into credit points. The conversion factor varies slightly depending on the type of subject (theory, practical, lab, etc.) and the department, but generally, a subject with 3 contact hours per week might be worth 3 credits, while a 2-hour lab might be worth 1 or 2 credits. The exact credit point assignment for each subject is specified in the syllabus or course curriculum.
* Total Credits per Semester: The total credits for a semester are the sum of the credit points for all the subjects you are taking that semester.
* Total Credits for the Degree: The total number of credits required to complete your degree (e.g., B.E., B.Tech) is pre-defined by the Anna University regulations for your specific program and branch. This is a fixed number, and you need to earn all of those credits to graduate.
In short, you don't *calculate* your credits; they are assigned to each subject beforehand. You simply add up the credits assigned to all your subjects for a given semester or for the entire duration of your program. Your grade in a subject affects your Grade Point Average (GPA) and Cumulative Grade Point Average (CGPA), but not the number of credits you earn for that subject.