Many students only look at their CGPA when results come out. If you understand how it is calculated, you can plan which courses deserve the most effort and set realistic targets.
Course units
Each course has a number of units (also called credit units or credit load), usually from 1 to 4 or more. Units show how much a course counts. A 3-unit course affects your GPA three times as much as a 1-unit course.
Grades and grade points
Many Nigerian universities use a 5-point scale similar to this:
| Score | Grade | Grade point |
|---|---|---|
| 70 to 100 | A | 5 |
| 60 to 69 | B | 4 |
| 50 to 59 | C | 3 |
| 45 to 49 | D | 2 |
| 40 to 44 | E | 1 |
| 0 to 39 | F | 0 |
Grading systems differ between universities and change over time. Some no longer use the E grade, for example. Always check your own student handbook.
Calculating your GPA
For each course, multiply the units by the grade point to get the quality points. Add the quality points, then divide by the total units.
GPA = total quality points ÷ total units
Worked example
| Course | Units | Grade | Point | Quality points |
|---|---|---|---|---|
| MTH 101 | 3 | A | 5 | 15 |
| CHM 101 | 3 | B | 4 | 12 |
| GST 101 | 2 | C | 3 | 6 |
| BIO 101 | 3 | B | 4 | 12 |
| PHY 101 | 3 | D | 2 | 6 |
| Total | 14 | 51 |
GPA = 51 ÷ 14 = 3.64 (to two decimal places).
CGPA
Your CGPA (cumulative GPA) uses all the courses you have taken so far: total quality points from every semester divided by total units from every semester. It is not simply the average of your semester GPAs, because semesters with more units count more.
Class of degree
Many universities use bands like these on the 5-point scale:
- First Class: 4.50 to 5.00
- Second Class Upper: 3.50 to 4.49
- Second Class Lower: 2.40 to 3.49
- Third Class: 1.50 to 2.39
- Pass: 1.00 to 1.49 (where still awarded)
Again, check your own handbook. The exact bands can differ.
What this means for your planning
- Units matter. An A in a 4-unit course lifts your GPA more than an A in a 1-unit course.
- Early semesters are easier to fix. As your total units grow, each new semester moves your CGPA less. That is why a strong start matters.
- Failed courses hurt twice: once when you fail, and again when you carry the course over and add its units again.