Calculating your CGPA/SGPA is not an uphill task, it requires little smart work. First you need to know the number periods per week of each subject .After that you will calculate the credits of each subject. Say in first you have 7 subjects :
*Physics: 3 lectures 1 tutorial
*Chemistry: 3 lectures 1 tutorial
*Math: 3 lectures 2 tutorials
*ECO: 3 lectures 1tutorial
*ELECTRICAL :2 lectures 1 tutorial
*Basic Electronics: 2 lectures 1 tutorial
*Engineering Drawing :3 classes
*Physics PRAC: 2 Classes
*Chemistry PRAC: 2 Classes
*Basic ELECTRICAL PRAC:2 Classes
Now each lecture has one credit and each prac or tutorial has 0.5 credit. So , in the above case
Physics,Chemistry,ECO has 3.5 credit each;
Math has 4 credit ;
Basic ELECTRICAL, Basic Electronics has 2.5 credit.
All practical have 1 credit.
Engineering Drawing has 1.5 because its classes are not considered as lectures but they are treated as tutorials.
This was all about calculating credits.
In each subject you get some grade, which you get according to your marks ,they have been given in below .Points have been allotted to each grade.
A+(85&above) ---------- 10
A(75-84) ---------- 9
B (65-74) ----------- 8
C (50-64) ---------- 6
D (40-49) ---------- 4
E (39 & below) ------ 2
If you get E grade you don’t pass the course,you will have to appear again in that course.
So your SGPA that is your grade point aggregate for semester is calculated as follow:
SGPA=∑{credit of subjectn*points u get in subject n}/total credits
CGPA=∑{credit of semester*SGPA of semester}/total credits so far
