How Is GPA Calculated? Step-by-Step Formula Guide
Your complete guide to understanding GPA math — from the basic formula to credit-weighted calculations, with worked examples at every step.
1. The GPA Formula
GPA (Grade Point Average) is a credit-weighted average of your course grades. The fundamental formula is:
In plain language:
- Convert each letter grade to quality points (a number on the 4.0 scale)
- Multiply quality points by credit hours for each course
- Add up all the weighted values (this is your total grade points)
- Divide by total credit hours attempted
2. Letter Grades → Quality Points
The standard 4.0 scale used by most US colleges:
| Letter Grade | Quality Points | Percentage (typical) |
|---|---|---|
| A+ | 4.0 (or 4.33) | 97–100% |
| A | 4.0 | 93–96% |
| A− | 3.7 | 90–92% |
| B+ | 3.3 | 87–89% |
| B | 3.0 | 83–86% |
| B− | 2.7 | 80–82% |
| C+ | 2.3 | 77–79% |
| C | 2.0 | 73–76% |
| C− | 1.7 | 70–72% |
| D+ | 1.3 | 67–69% |
| D | 1.0 | 63–66% |
| D− | 0.7 | 60–62% |
| F | 0.0 | Below 60% |
3. Worked Example: Semester GPA
Let's calculate GPA for a typical semester:
| Course | Grade | Points | Credits | Grade Points |
|---|---|---|---|---|
| English 101 | A | 4.0 | 3 | 12.0 |
| Calculus I | B+ | 3.3 | 4 | 13.2 |
| Biology 101 | A− | 3.7 | 4 | 14.8 |
| History 101 | B | 3.0 | 3 | 9.0 |
| Art 100 | A | 4.0 | 2 | 8.0 |
| Totals | 16 | 57.0 | ||
4. Cumulative GPA
Cumulative GPA combines all semesters into one number. You don't average your semester GPAs — you use the total grade points and total credits across all terms:
Example:
- Semester 1: 48.0 grade points, 15 credits (GPA = 3.20)
- Semester 2: 57.0 grade points, 16 credits (GPA = 3.56)
- Cumulative: (48.0 + 57.0) ÷ (15 + 16) = 105.0 ÷ 31 = 3.387 → 3.39
Notice the cumulative GPA (3.39) is not the simple average of 3.20 and 3.56 (which would be 3.38). The difference comes from the unequal credit loads.
Use the Cumulative GPA Calculator →
5. Weighted vs. Unweighted GPA
Unweighted GPA (4.0 scale)
Every course is graded on the same 4.0 scale regardless of difficulty level. An A in AP Chemistry = an A in Regular Art = 4.0.
Weighted GPA (5.0 scale)
Advanced courses receive bonus points to reflect their difficulty:
| Course Level | Bonus Points | A = |
|---|---|---|
| Regular | +0.0 | 4.0 |
| Honors | +0.5 | 4.5 |
| AP / IB | +1.0 | 5.0 |
Weighted GPA is primarily used by high schools. Most colleges recalculate your GPA using their own methodology.
Full guide: Weighted vs. Unweighted GPA →
6. Special Cases
Pass/Fail Courses
Pass (P) usually doesn't count toward GPA. Credits are earned but quality points are excluded. Fail (F) handling varies by school — some exclude it, others count it as 0.0.
Repeated Courses
Schools handle retakes differently: grade replacement, count all attempts, or average them. Application services (LSAC, AMCAS) have their own rules too.
Repeat/forgiveness policy guide →
Withdrawals
W (Withdrawal) typically doesn't affect GPA. WF (Withdrawal Failing) usually counts as an F (0.0). Always check your school's specific policy.
Quarter vs. Semester Credits
Schools on quarter systems use a multiplier: 1 quarter credit = 0.667 semester credits. This matters when transferring or applying to graduate programs.
Quarter ↔ Semester conversion guide →
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