How it works
GPA measures academic performance as a single number. It converts your letter grades into points (A = 4.0, B = 3.0, and so on), then averages them—but with a twist: courses worth more credit hours carry more weight. A 4-credit course pulls the average harder than a 1-credit elective.
This calculator multiplies each grade's point value by its credit hours, sums all those products, and divides by your total credit hours. That's your weighted GPA.
The formula
GPA = (Σ grade points × credit hours) ÷ Σ credit hours
Worked example
Imagine you take four courses in a semester:
| Course | Grade | Credit Hours | Grade Points | Points × Credits |
|---|---|---|---|---|
| Biology | A | 4 | 4.0 | 16.0 |
| History | B+ | 3 | 3.3 | 9.9 |
| Spanish | A− | 3 | 3.7 | 11.1 |
| Psychology | B | 2 | 3.0 | 6.0 |
| Total | 12 | 43.0 |
Step 1: Convert each letter grade to its point value.
- A = 4.0
- B+ = 3.3
- A− = 3.7
- B = 3.0
Step 2: Multiply each grade by its credit hours.
- Biology: 4.0 × 4 = 16.0
- History: 3.3 × 3 = 9.9
- Spanish: 3.7 × 3 = 11.1
- Psychology: 3.0 × 2 = 6.0
Step 3: Add up all the weighted points.
- 16.0 + 9.9 + 11.1 + 6.0 = 43.0
Step 4: Divide by total credit hours.
- 43.0 ÷ 12 = 3.58 GPA
Notice that Biology (4 credits) and Spanish (3 credits) had more influence than Psychology (2 credits). If you'd taken all courses as equal credit, the unweighted average would be (4.0 + 3.3 + 3.7 + 3.0) ÷ 4 = 3.5. The weighted version is slightly higher because your highest grades were in high-credit courses.
Common mistakes
Forgetting to include credit hours: Omitting credit hours will give you a simple average instead of a weighted GPA. Always pair each grade with its course credits.
Using the wrong grade scale: Some schools use A+ = 4.3 or cap A at 4.0 with no A−. Verify your institution's scale before calculating; using the wrong one will skew your result.
Excluding failed or retaken courses: If you retook a course, include both attempts (or follow your school's policy—some count only the higher grade, others average them). Excluding a low grade artificially inflates your GPA.
Treating all semesters equally: If you're calculating cumulative GPA, weight each semester by its total credits, not as a simple average of semester GPAs. A semester with 18 credits should count more than one with 12.
This calculator provides an estimate based on standard US grading scales. For official GPA verification, consult your school's registrar.