How to calculate CGPA

1. Write down each completed semester’s SGPA and the total credits that semester carried. Both are printed on the grade card — use the credit total, not the number of subjects.
2. Multiply the two, semester by semester. These products are sometimes called credit points.
3. Add all the products, and separately add all the credits.
4. Divide the first total by the second. Truncate to two decimals rather than rounding up.

That is the whole method. Everything below is about getting the inputs right, which is where the mistakes actually are.

CGPA = 774.2 ÷ 94 = 8.23. The plain average of the four SGPAs is 8.22, which is close here only because the four credit loads are close. Put a 30-credit project semester at a weak grade into the same degree and the two figures separate by half a point. The CGPA calculator shows both, so the size of the gap is visible rather than assumed.

Then you are a level lower down and the same operation runs first. Multiply each subject’s grade point by its credits, add, divide by the semester’s credits — that gives the SGPA. Five subjects graded 9, 8, 7, 10 and 6 against credits of 4, 4, 3, 2 and 1 come to 115 weighted points over 14 credits, so the SGPA is 8.21.

Do that for every semester, then bring the SGPAs back to the table above. The SGPA calculator handles the lower level and how SGPA works walks through it in full.

• Credits, not subjects. Six subjects worth 18 credits weigh less than five worth 24. Use the credit total the grade card prints.
• Backlogs. A subject cleared in a later attempt normally enters the semester in which it was cleared, at the grade obtained. Some universities cap the grade on a re-attempt. Leave it out and your figure is too high.
• Audit and non-credit courses. Zero credits means zero contribution. Entering them with zero credits is harmless; entering them with credits they do not carry is not.
• A semester still in progress. No declared result means no SGPA and no earned credits. It stays out until results are published.

A weighted average must land between the smallest and the largest of the numbers being averaged. If your semesters run from 7.80 to 8.60, the CGPA has to sit somewhere in that range. Get 8.9 or 7.2 and you have not found an unusual result — you have made an arithmetic error, almost always by mismatching a semester’s SGPA with another semester’s credits.

A second check: the answer should lean toward the semesters with the heaviest credit loads. In the table above, semester 3 is both the strongest and the heaviest, which is why 8.23 sits slightly above the plain average of 8.22.

For eight semesters this is faster and less error-prone than a calculator. Put SGPAs in column B and credits in column C, then one formula does the whole thing:

=SUMPRODUCT(B2:B9, C2:C9) / SUM(C2:C9)

SUMPRODUCT multiplies the pairs and adds the results in one step, which is exactly the operation described above. The same formula works for subjects and credits when you are computing an SGPA. Format the cell to two decimals, and remember that a spreadsheet rounds where your university truncates — 8.236 will display as 8.24, not 8.23.

A CGPA after four semesters is a real figure and the one most placement portals ask for. It simply covers four semesters instead of eight. What you cannot do is mix a completed semester with one that has no result yet.

One consequence worth knowing early: each new semester is a smaller fraction of a growing credit total, so a weak semester six moves the cumulative figure far less than a weak semester one. By the second half of a degree the number becomes hard to shift in either direction.