How to Calculate GPA and CGPA: A Worked Credit-Unit Example

To calculate GPA and CGPA, multiply each course’s grade point by its credit units, add the resulting quality points, then divide by the total included credit units. GPA covers one semester. CGPA combines the included courses across semesters.

The important detail is weighting. A three-unit course counts three times as much as a one-unit course. Two semester GPAs should not receive equal weight when their unit totals differ.

Table of Contents

Before you start: collect these three details

Each course’s credit units from your result or approved course record.
The grade point assigned to each result under your programme’s grading scale.
Your institution’s rules for failed, repeated, transferred and pass/fail courses.

Use your programme handbook rather than a grading table copied from another university. The example below uses illustrative points on a five-point scale, not a declaration of your school’s current grading rules.

How to calculate GPA: a worked example

Suppose your semester contains these three courses:

Illustrative semester GPA calculation
Course	Credit units	Grade point	Quality points
Course A	3	5	3 × 5 = 15
Course B	2	4	2 × 4 = 8
Course C	1	3	1 × 3 = 3
Total	6	Not added	26

GPA = total quality points ÷ total included credit units = 26 ÷ 6 = 4.33, rounded to two decimal places.

Do not divide 26 by three merely because you took three courses. The denominator is the six credit units. Also avoid averaging the grade points directly: (5 + 4 + 3) ÷ 3 gives 4.00, which ignores the different course weights.

How to calculate CGPA across semesters

Keep the underlying quality-point and unit totals from every semester. Suppose the next semester adds 54 quality points across 14 units.

Combining two semesters
Period	Quality points	Credit units
First semester	26	6
Second semester	54	14
Combined	80	20

CGPA = (26 + 54) ÷ (6 + 14) = 80 ÷ 20 = 4.00.

The separate semester GPAs are approximately 4.33 and 3.86. Their simple average is about 4.10, not the correct 4.00 CGPA. That shortcut gives the six-unit semester too much influence.

If you have only semester GPAs

Multiply each semester GPA by its included unit total, add those products and divide by the combined units. However, GPAs printed to two decimal places are rounded. Reconstructing quality points from them can introduce a small difference. Use the original quality-point totals where available, especially when checking a classification boundary.

A reusable result-checking worksheet

Create one row per course with columns for course code, credit units, grade point and quality points.
Multiply units by grade point for each included course.
Add the quality-point column.
Add the included credit-unit column.
Divide the first total by the second.
Compare your result with the official record and note any difference.

If using a spreadsheet with units in B2:B10 and grade points in C2:C10, enter =B2*C2 in D2 and copy it down. Then use =SUM(D2:D10)/SUM(B2:B10). Adjust the row range to your actual courses and check for missing entries before accepting the answer.

Why does your calculation differ from the portal?

First check course units, omitted courses, grade-point mapping and rounding. Next check how your institution treats repeats and failed or transferred courses. Do not assume a repeat automatically erases the earlier attempt, or that a zero-point result contributes no units. Ask your adviser to confirm the approved treatment.

When reporting a discrepancy, send the course codes, units, grades, your calculation and the official result privately to the relevant academic office. A specific comparison is easier to investigate than “my CGPA is wrong.”

Does this tell you your class of degree?

Not by itself. Apply your programme’s approved classification rules after establishing the correct CGPA. Do not assume another institution’s boundaries or rounding policy applies to you.

Official source

The UNILAG DLI handbook provides an institutional example of weighted GPA calculation. Check your own current handbook for the rules that govern your record.