How to calculate GPA and CGPA
Your GPA is a credit-weighted average of your grade points. This guide shows the formula, a full worked example for one semester and for your cumulative CGPA, and the mistakes that give people the wrong number.
The short version
- List every course. Write down each course's credit hours and the grade points your school gives for the grade you earned.
- Find the quality points. Multiply grade points by credit hours for each course.
- Add up two totals. Add all the quality points, and separately add all the credit hours.
- Divide. GPA = total quality points ÷ total credit hours. Round only at the end.
Skip the arithmetic. The free GPA Calculator does this for you, shows the formula and the working with your own numbers, and runs in your browser - nothing you type is uploaded. Also useful: Grade Calculator, Final Grade Calculator.
The GPA formula
Grade point average weights each course by how many credit hours it is worth, so a 4-credit course moves your GPA more than a 1-credit one.
A worked example: one semester
A student takes four courses on a 4.0 scale.
| Course | Credits | Grade | Points | Quality points |
|---|---|---|---|---|
| Calculus | 4 | A | 4.0 | 16.0 |
| English | 3 | B+ | 3.3 | 9.9 |
| Physics | 4 | B | 3.0 | 12.0 |
| History | 2 | A- | 3.7 | 7.4 |
| Total | 13 | 45.3 |
Calculating your new CGPA
Your cumulative GPA (CGPA) works the same way across every semester. You do not need the old courses - only your previous CGPA and your previous total credits, because CGPA × credits gives back the old quality points.
Why you cannot average your GPAs
Averaging 3.00 and 3.48 gives 3.24, which is wrong. The 30 earlier credits must count for more than this semester's 13. The simple average of semester GPAs only works if every semester had exactly the same number of credits.
Scales are not the same everywhere
Many US colleges use a 4.0 scale with plus and minus grades (A- is 3.7, B+ is 3.3). Some systems use a 5-point scale, and many universities publish their own table with values such as 3.67 or 3.33. Some US high schools add a point for honours or AP courses, which is called a weighted GPA. The formula is identical in every case - only the grade points change - so use the exact points from your own transcript or handbook.
Common mistakes
- Forgetting to weight by credits and just averaging the grade points.
- Using the wrong points for plus and minus grades.
- Counting pass/fail or audited courses that your school leaves out of GPA.
- Ignoring your school's rule for repeated courses (some replace the old grade, some average both).
- Rounding each course before adding. Keep full precision and round the final answer.
CGPA to percentage conversion is not covered by the formula above: every university defines its own, so use the conversion your institution publishes.