The CGPA is the cumulative Grade Point Average of all the courses you registered for in the university/polytechnic. It can be said differently as the total grade points are divided by the total units of the courses registered.
The calculation of GPA in Nigerian polytechnics follows nearly the same procedure as that of Nigerian Universities. However Nigerian polytechnics make use of the following grading system in the calculation of GPA and the awarding of Ordinary National Diploma (OND) and Higher National Diploma (HND):
Polytechnics Grading System Table:
| Score (%) | Grade | Grade Point | Final CGPA | Class Of Degrees |
| 100-80 | A | 4.00 | 3.50 – 4.00 | Distinction |
| 79-70 | AB | 3.50 | 3.00 – 3.49 | Upper Credit |
| 60-69 | B | 3.00 | 2.50 – 2.99 | Lower Credit |
| 59-50 | BC | 2.50 | 2.00 – 2.49 | Pass |
| 49-40 | C | 2.00 | 0.00 – 1.99 | Fail |
Assuming you offer the following courses and obtain scores that correspond to the following grades that lead to the distribution on the tables below. then you will your GPA as follows:
| Course Code | Credit Unit | Grade | Grade Points | Quality Points (CU X GP) | Total Points |
| Gsp 101 | 2 | C | 2.00 | 2 x 2.00 | 4.00 |
| Gsp 105 | 2 | C | 2.00 | 2 x 2.00 | 4.00 |
| Gsp 111 | 2 | A | 4.00 | 2 x 4.00 | 8.00 |
| Gsp 201 | 2 | AB | 3.50 | 2 x 3.50 | 7.00 |
| Cos 101 | 2 | BC | 2.50 | 2 x 2.50 | 5.00 |
| Sta 131 | 2 | B | 3.00 | 2 x 3.00 | 6.00 |
| Mth 221 | 3 | C | 2.00 | 3 x 2.00 | 6.00 |
| Total Credit Units | 15 | 44 |
First Semester OND1:
GPA = Total points/Total Credit Units = 44.00/15 = 2.9.
Therefore your first semester ND1 GPA = 2.9.
Second Semester OND1 GPA Calculation Assuming you offer the following courses and obtain scores that correspond to the following grades that lead to the distribution on the tables below. then you will your GPA as follows:
| Course Code | Credit Unit | Grade | Grade Points | Quality Points (CU X GP) | Total Points |
| Chm 112 | 2 | A | 4.00 | 2 x 4.00 | 8.00 |
| Gsp 208 | 2 | E | 0.00 | 2 x 0.00 | 0.00 |
| Gsp 106 | 2 | c | 2.00 | 2 x 2.00 | 4.00 |
| Gsp 202 | 2 | C | 2.00 | 2 x 2.00 | 4.00 |
| Bio 152 | 3 | B | 3.00 | 3 x 3.00 | 9.00 |
| Phy 196 | 2 | BC | 2.50 | 2 x 2.50 | 5.00 |
| Glg 142 | 3 | C | 2.00 | 3 x 2.00 | 6.00 |
| Total Credit Units | 16 | 36 |
Second Semester GPA = Total points/Total Credit Units = 36.0/16 = 2.21875= 2.25.
Therefore your second semester ND1 GPA = 2.25.
Not, to calculate your cumulative grade point average (CGPA) for ND1 (first year), you add your ND1 first semester and second semester GPA and divide the result you obtain by two (2), i.e. the number of semesters. This is simply finding the average.
Here it goes:
Your OND1 CGPA = (First Semester ND1 GPA + Second semester ND1 GPA) / 2 = (2.9 + 2.25) / 2.
CGPA = 5.15 / 2 = 2.575 = 2.58
The process is repeated for every semester result.
That should be all on how to calculate GPA (Grade Point Average) and CGPA (Cumulative Grade Point Average) in Nigerian Polytechnics.