Students often average their letter grades directly and get a number that doesn't match their transcript. The missing ingredient is credit weighting — here's how GPA and CGPA are actually computed.
GPA vs. CGPA — what's the difference?
GPA (Grade Point Average) typically refers to your average for a single term or semester. CGPA (Cumulative GPA) is the same calculation but across every term you've completed so far — your entire academic record to date. The math is identical; CGPA just includes more courses over more time.
Enter your courses and credits to get an accurate, credit-weighted GPA or CGPA instantly.
Open GPA CalculatorWhy you can't just average the letter grades
A common mistake is averaging grade points as if every course counts equally: (4.0 + 3.0 + 2.0) ÷ 3 = 3.0. But a 4-credit course should count more than a 1-credit elective. The correct method is credit-weighted:
GPA = (sum of grade-point × credits for each course) ÷ (total credits)
A single high-credit course with a poor grade can pull your average down more than a low-credit one — which is exactly why weighting matters, and why hand-averaging letter grades gives the wrong number.
A worked example
| Course | Grade | Points | Credits | Points × Credits |
|---|---|---|---|---|
| Math | A | 4.0 | 4 | 16.0 |
| History | B | 3.0 | 3 | 9.0 |
| Art elective | A | 4.0 | 1 | 4.0 |
Total points: 29.0. Total credits: 8. GPA = 29.0 ÷ 8 = 3.63 — not the 3.67 you'd get by averaging the three grade points directly, because the low-credit A elective is weighted down.
4.0 scale vs. 10-point scale
The US commonly uses a 4.0 scale; many other countries use a 10-point scale. They aren't simply proportional — a rough conversion divides a percentage by 9.5 for the 10-point scale, versus a linear ×4/100 (or standardized letter bands) for the 4.0 scale. If you're applying internationally, always check the receiving institution's preferred conversion rather than assuming a straight ratio — see our Percentage to GPA tool for both methods side by side.
Keep your credits accurate
The single biggest source of a wrong GPA calculation isn't the math — it's using the wrong credit values for one or two courses. Double-check the official credit hours from your transcript before calculating, especially for labs, electives, or half-credit courses that are easy to mis-enter.