HOW TO CALCULATE GPA AND CGPA

WHAT IS THIS GUIDE ABOUT?
This guide is written to assist university or college students to understand more about the grading system at tertiary education level. Students are often trapped under the pretense that once they've failed, their grades can never go up again. This is fairly untrue in most of the cases, however it is important to note that not all tertiary education system follows the same CGPA system. What I have tabled out below are applicable to local Universities and most UK based universities.

WHAT IS CGPA?

Ultimately, CGPA is where everything boils down to in your studies. It stands for CUMULATIVE GRADE POINT AVERAGE, hence CGPA, which is an accumulation of all your grade points divided to every single credit your take. CGPA is also the determining factor of whether you get to graduate with 1st class, 2nd class upper, 2nd class lower or 3rd class. However, the minimum point for each class differs from university to university. for example classifies 1st class as 3.70 and above and 2nd class upper from 3.00 to 3.69

WHAT IS CALCULATED?
CGPA is calculated based on all subjects that you take,  each subjects usually comes with a credit value,  some less important subjects carry between 1 to 2 credits or units, more important ones carry 3 to 4, as seen in department courses, also, there are subjects categorized as "compulsory attendance only" which usually carry 0 credits. These subjects hold no value, but failing it (due to poor attendance or whatever) will still hold u down from graduating successfully. (not seen in Nigeria Universities)

HOW IS CGPA CALCULATED?
For each subject that you've successfully taken, a grade will be issued after the final examination; these grades each carry a specific point value. Typically, A carries 4.00, B carries 3.00 and C carries 2.00. Each of these points will be calculated based on the credit rating of each subject, and later summed up to give u your GPA for that particular semester. for example:
semester 1
subject P (6 credits): B = 3.00
subject N (2 credits): A = 4.00
subject O (3 credits): C = 2.00

(6 x 3.00) + (2 x 4.00) + (3 x 2.00) = 32 total grade point for 11 credits. Hence, your GPA for semester 1 is:
32 / 11 = 2.91 GPA for semester 1. Since this is your first semester, your GPA is also your CGPA.

semester 2
subject P (6 credits): A = 4.00
subject Q (3 credits): B = 3.00
subject R (3 credits): E = 0.00 (FAIL)
subject S (2 credits): B = 3.00

(6 x 4.00) + (3 x 3.00) + (3 x 0.00) + (2 x 3.00) = 39 total grade point for 14 credits. hence your GPA for semester 2 is:
39 / 14 = 2.79 GPA for sem 2

Now that this is your second semester, your CGPA will be calculated by combining the two,  however, a direct average is wrong. CGPA is calculated NOT based on the average of GPAs per semester, but based on grade points per credit that u take. To calculate your CGPA based on the two semesters above:

[(total grade point for semester 1) + (total grade point for semester 2)] / total credit taken in all semesters

[(32) + (39)] / (11 + 14) = 2.84 CGPA
now, let's try the next semester where u retake the failed subject:

semester 3
subject R (3 credits): A = 4.00 (REPEATED SUBJECT)
subject T (3 credits): B = 3.00
subject U (3 credits): B = 3.00
subject V (3 credits): B = 3.00

(3 x 4.00) + (3 x 3.00) + (3 x 3.00) + (3 x 3.00) = 39 total grade point for 12 credits. hence your GPA for semester 3 is:
39 / 12 = 3.25 GPA.

Now, how do you calculate your CGPA when u have a repeated subject? here's the main rule: u recalculate the repeated subject by replacing the old grade with the new one, it means, in your CGPA calculation, u never failed your subject R, u actually scored A! let’s see what it looks like:

[(grade points for sem 1) + (grade points for sem 2 excluding the failed subject) + (grade points for sem 3)] / [(credit for sem 1) + (credit for sem 2 excluding the failed subject) + (credit for sem 3)]
[(32) + (39 - 0) + (39)] / [(11) + (14 - 3) + (12)] = 110 / 34 = 3.24 CGPA!

A lot of students made the mistake of including the failed subject into the calculation despite having repeated it. here's what the wrong calculation usually looks like:

IMPLICATION
wrong calculations would lead to students being afraid to fail, simply becouse the impression that failed subjects would drag the CGPA even further down. This is wrong, repeating the failed subject replaces the old grades. In your CGPA, it is as if you've never failed before. Most students would simply accept a C- or D+, which is usually the minimum passing rate, in hope that they don’t have to ever repeat the subject, and hopefully score more subjects in time. Thing is, once you've got a D+/C-, it's very hard to catch up and drag your pointers up. I strongly advise students who ultimately concerned for their grades to DARE to fail and repeat it again. Of course, certain subjects are big enough that repeating means u have to extend another semester. Well, if it means graduating between a 2nd class lower and a 2nd class upper, why not?
good luck!