Guide
How to Calculate GPA, CGPA and Percentage (Any Grading Scale)
GPA and CGPA are credit-weighted averages of your grade points. This guide shows the formula, works through two semesters step by step, explains why averaging your semester GPAs gives the wrong answer, and what to know before converting CGPA to a percentage.
Published
What you need before you start
- Your grades for each course (A, B+ and so on) and each course’s credit hours. Both are on your result card or transcript.
- Your university’s grading scale: the grade points for each letter grade. Scales differ between universities, so check yours in the student handbook or on the examinations page.
The example below uses a common 4.0 scale (A = 4.0, A- = 3.67, B+ = 3.33, B = 3.0, C+ = 2.33). It is only an example, not any university’s official scale.
How to calculate GPA for one semester
- For each course, multiply its credit hours by the grade points for your grade. The result is called quality points.
- Add up the quality points for all the semester’s courses.
- Add up the credit hours.
- Divide total quality points by total credit hours.
| Course | Credit hours | Grade (points) | Quality points |
|---|---|---|---|
| Course 1 | 3 | A (4.0) | 12.00 |
| Course 2 | 3 | B+ (3.33) | 9.99 |
| Course 3 | 4 | B (3.0) | 12.00 |
| Course 4 | 2 | A- (3.67) | 7.34 |
| Course 5 | 3 | C+ (2.33) | 6.99 |
| Total | 15 | — | 48.32 |
GPA = 48.32 ÷ 15 = 3.22 (3.2213 before rounding). Note that the 4-credit course counts for more than the 2-credit course: that is the whole point of weighting by credit hours.
How to calculate CGPA across semesters
CGPA uses the same method over everything you have taken so far. Suppose semester 2 has 13 credit hours: A- (3 credits), B (3), B+ (3), A (3) and a 1-credit lab with an A. Its quality points are 11.01 + 9.00 + 9.99 + 12.00 + 4.00 = 46.00, so its GPA is 46 ÷ 13 = 3.54.
CGPA = (48.32 + 46.00) ÷ (15 + 13) = 94.32 ÷ 28 = 3.37 (3.3686).
The CGPA, Percentage & Merit Calculator does this for you: set your university’s grading scale, add your courses, and enter your previous CGPA and credit hours to get the new CGPA.
Rounding, failed courses and repeated courses
- Rounding: universities differ. Some round to two decimals, some cut off (truncate) instead: Carleton University, for example, truncates3. At a cut-off like 3.00 this can matter, so check your university’s rule.
- Failed courses: an F usually counts as 0 grade points with its credit hours still included, which pulls the GPA down.
- Repeated courses: rules vary; many universities count only the better or the latest attempt. Your transcript and handbook are the authority.
How to calculate a percentage from marks
Add up the marks obtained across all subjects and divide by the total marks available, then multiply by 100. For example, 78/100, 65/75 and 140/200 give 283 ÷ 375 × 100 = 75.47%. Averaging the three percentages (78%, 86.67%, 70%) would give 78.22%, which is wrong for the same reason as averaging GPAs: the subjects have different totals.
CGPA to percentage: why there is no single formula
Many websites present one “HEC formula” for converting CGPA to a percentage. HEC’s own policy guidelines for the semester system do not work like that: they give a table in which each grade covers a range of grade points and marks, and a student with a CGPA in a range is given the minimum percentage for that range; in HEC’s example, a CGPA of 3.00 corresponds to 71%1. The same guidelines let institutions choose how they grade, and universities publish their own conversion rules.
So if an employer, scholarship or admission form asks for a percentage, use the conversion printed on your transcript or published by your university, not a general formula. The same applies in reverse: converting a percentage into a CGPA is not exact, because a grade covers a range of marks.
Common questions
What is the difference between GPA and CGPA?
GPA covers one semester. CGPA (cumulative GPA) covers every semester so far, weighted by credit hours.
How do I calculate CGPA for 2 semesters?
Add the quality points of both semesters and divide by the credit hours of both semesters. In the example above: (48.32 + 46.00) ÷ 28 = 3.37.
Can I calculate GPA from marks?
Only through your university’s grading table: first turn each course’s marks into a letter grade and grade points using the published ranges, then apply the GPA formula.
Is 3.0 CGPA good?
It depends on the requirement you are measuring against. HEC’s undergraduate policy sets a minimum CGPA of 2.00 out of 4.00 for completing an associate degree2, while scholarships and admissions often ask for more. Check the specific requirement.
Sources
- Higher Education Commission (HEC): Policy Guidelines for Implementation of Uniform Semester System — section 14: the credit-hour formulas for GPA and CGPA; section 13.1: grade-to-percentage table, the minimum-of-range rule and the 3.00 → 71% example.
- Higher Education Commission (HEC): Undergraduate Education Policy — minimum CGPA of 2.00 out of 4.00 for an associate degree.
- Carleton University Academic Advising: CGPAs — a university that calculates GPA as grade points weighted by credits and truncates rather than rounds.