GPA & CGPA — The Complete Guide
GPA is just a weighted average wearing an academic costume: each grade gets converted to a number of "grade points," each course's contribution is weighted by its credit hours, and the whole thing is averaged the same way a weighted mean averages anything else — bigger weights (more credits) pull the result more.
Worked Example — Semester GPA
3 credits of A (4.0): 3 × 4.0 = 12.0
4 credits of B+ (3.3): 4 × 3.3 = 13.2
3 credits of A- (3.7): 3 × 3.7 = 11.1
GPA = (12.0 + 13.2 + 11.1) ÷ (3+4+3) = 36.3 ÷ 10 = 3.63
Why You Can't Just Average Two GPAs Directly
A common mistake: averaging last semester's 3.8 GPA with this semester's 3.2 GPA as (3.8+3.2)/2 = 3.5. That's only correct if both semesters had exactly the same number of credit hours. If last semester was 12 credits and this one is 18, the heavier semester should count more — which is exactly why the cumulative mode on this page weights each GPA by its own credit hours rather than averaging them as if they were equal.
A Note on Grading Scales
This calculator uses the standard US 4.0 scale with plus/minus adjustments. If your institution uses a different scale — a 10-point CGPA system, a percentage-based system, or a scale that extends above 4.0 for A+ — the underlying math is identical; just use the cumulative mode with GPA figures already expressed in your institution's scale, since it's a pure weighted average regardless of what the numbers represent.