this is grading system how we calculate grades

There are different grading systems like CGPA or Cummulative Grade Point Average, SGPA or Semester Grade Point Average etc. Now you need to read the official brochure of your college / university where you will find the grading system along with the formulae and the procedure of calculation.

Also some institutes gives grades such as A, A+, B etc. This are done on the basis of the Percentage marks obtained as per there criteria. So the grading system and notation varies from colleges to colleges. So you should check the one of your institute in order to maintain the relevancy of your system.

Have a great eve!