Your GPA is a weighted average, with each course being weighted according to its allotted credit hours, rather than a simple average of letter grades.
The GPA Formula
Each letter grade is first translated into numerical grade points in order to get your Grade Point Average. After adding the products and multiplying each class grade point by its credit units, you divide the result by the total number of credits attempted.
GPA = Σ(grade points × credit hours) ÷ Σ(credit hours)
Standard 4.0 Grading Scale
Here is an illustrative 4.0 scale. Institutions differ, so use your own school’s official grade points:
- A = 4.0 | A- = 3.7
- B+ = 3.3 | B = 3.0 | B- = 2.7
- C+ = 2.3 | C = 2.0 | C- = 1.7
- D = 1.0 | F = 0.0
Step-by-step semester calculation
Suppose you completed four courses this semester:
- Calculus (4 credits): Grade A (4.0) → 4 × 4.0 = 16.0 grade points
- Physics (4 credits): Grade B+ (3.3) → 4 × 3.3 = 13.2 grade points
- English Lit (3 credits): Grade A- (3.7) → 3 × 3.7 = 11.1 grade points
- History (3 credits): Grade B (3.0) → 3 × 3.0 = 9.0 grade points
Total Quality Points = 16.0 + 13.2 + 11.1 + 9.0 = 49.3
Total Credit Hours = 4 + 4 + 3 + 3 = 14 credits
GPA = 49.3 ÷ 14 = 3.52 GPA.
Why credit hours matter
Your GPA is affected four times more by a four-credit lab science course than by a one-credit elective in physical education. Because of this, credit hours are crucial when determining how a course may affect your overall GPA.
Try it yourself
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