How this calculator works
This calculator computes an unweighted GPA on the standard US 4.0 scale from a list of letter grades and their matching credit hours. Enter both lists in the same order — grade for course 1, credits for course 1, and so on — and it returns the overall GPA along with a course-by-course breakdown.
GPA is a weighted average where the weight is each course's credit hours, so a 4-credit class affects the result more than a 1-credit class. This is the same math as any weighted average, just applied to grade points instead of raw scores.
The formula and grade scale
GPA = Σ(grade points × credit hours) ÷ Σ(credit hours)A/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+ = 1.3, D = 1.0, D- = 0.7, F = 0.0This is the most widely published US 4.0 scale. Individual schools vary — some award A+ a 4.3, and some don't award plus/minus grades at all — so always confirm against your school's own scale for an official record.
Worked example: A, B+, A- across three courses
- A (4.0 points) in a 3-credit course: 4.0 × 3 = 12.0 quality points.
- B+ (3.3 points) in a 4-credit course: 3.3 × 4 = 13.2 quality points.
- A- (3.7 points) in a 3-credit course: 3.7 × 3 = 11.1 quality points.
- Total quality points: 12.0 + 13.2 + 11.1 = 36.3. Total credits: 3 + 4 + 3 = 10. GPA = 36.3 ÷ 10 = 3.63.
Frequently asked questions
Why do heavier courses (more credits) affect my GPA more?
GPA is a credit-weighted average, so a 4-credit course contributes four times as many quality points as a 1-credit course with the same letter grade. This mirrors how much coursework each class actually represents.
Is A+ really worth 4.0, not more?
This calculator uses 4.0 for A+, the most common convention in the US, since a 4.0 scale has no higher value to give. Some schools use a 4.3 scale specifically to reward A+ separately — check your institution's official grading policy if your transcript shows a value above 4.0.
Does this match my school's official GPA?
It should, for schools using the standard unweighted 4.0 scale shown here. Schools with weighted GPAs (extra points for honors or AP courses) or different plus/minus values will produce a different official number — this calculator is for the common case and for estimating before grades post.
What if I enter a grade that isn't on the list, like 'P' for pass?
Pass/fail, incomplete, and withdrawal grades typically don't carry grade points and are usually excluded from official GPA calculations entirely. Leave them out of both lists rather than trying to assign them a letter-grade equivalent.
Can I calculate my GPA without knowing exact credit hours?
Not accurately — GPA is a credit-weighted average, Σ(grade points × credit hours) ÷ Σ(credit hours), so a course's credit hours change how much it counts. In the worked example, a 4-credit B+ contributes 13.2 quality points, more than the 3-credit A-'s 11.1 quality points, even though A- (3.7) is the higher letter grade than B+ (3.3) — the credit hours, not just the grade, decide the impact.