How GPA Is Calculated
Quick answer. Your GPA is the credit-weighted average of every graded course on your transcript. Multiply each course's grade-point value by its credit hours, sum the results, then divide by the total credit hours.
The formula
GPA = sum(grade_points × credit_hours) / sum(credit_hours)
That's it. Every GPA, on every scale, in every system, comes from this formula. What changes between systems is how grades map to points and which grades count.
Grade-to-point mappings
The standard US 4.0 scale with plus and minus modifiers:
| Letter | Points | |---|---| | 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 | 0.0 |
Cornell, MIT, BU, and a few others cap A+ at 4.3 instead of 4.0. LSAC uses A+ = 4.33 for law school applications. AMCAS treats A+ as 4.0 like everyone else.
A worked example
Three courses this semester:
- Biology, 4 credits, A (4.0)
- Calculus, 3 credits, B+ (3.3)
- Spanish, 3 credits, A- (3.7)
The math:
points = (4.0 × 4) + (3.3 × 3) + (3.7 × 3)
= 16 + 9.9 + 11.1
= 37.0
credits = 4 + 3 + 3 = 10
GPA = 37.0 / 10 = 3.70
Your semester GPA is 3.70.
What's excluded
These grades appear on your transcript but don't enter the GPA math:
- P, NP, CR, S, U. Pass/Fail and credit-only courses.
- W, WD, WP. Withdrawals. A regular W doesn't hurt your GPA but appears on the transcript.
- AU, AUD. Audited courses. No credit, no GPA impact.
- I, INC. Incompletes, until a final grade replaces them.
- NR. Not Reported.
A small number of schools convert punitive withdrawals (WF) to an F for GPA purposes. Check your registrar.
Semester vs. cumulative
Your semester GPA is the math above applied to one term. Your cumulative GPA is the same math applied to every course you've ever taken at your institution, weighted by credits.
A 3.0 GPA in one 15-credit semester moves a cumulative GPA by different amounts depending on the credits already on your record. After 60 credits at 3.8, that 3.0 semester drops you to 3.64. After 120 credits, the same semester drops you to 3.71.
How to recover from a bad term
If your current cumulative GPA is G over C credits and you want to reach target T with N future credits, you need to earn:
GPA_needed = (T × (C + N) − G × C) / N
If the answer is above 4.0, the target is mathematically impossible in that timeframe. Adjust either N (take more credits) or T (lower the goal).
Weighted vs. unweighted
Unweighted GPA uses the simple 4.0 scale above. Weighted GPA adds bonuses for course difficulty:
- Honors: +0.5
- AP: +1.0
- IB: +1.0
A weighted A in AP Calculus earns 5.0 grade points. A weighted A- in Honors English earns 4.2.
UC uses its own weighting rules with an 8-semester cap and freshman-year exclusion. See the UC GPA calculator for the details.
Quarter credits vs. semester credits
If your school operates on quarter terms (UCLA, U Chicago, Northwestern, Stanford), your "credits" are quarter credits. To convert to semester credits, multiply by 0.667.
AMCAS does this automatically during verification. Other applications expect you to convert before submitting.
Why your school's GPA might differ from a recalculation service
When you apply to medical school, law school, or for some scholarships, a third party recalculates your GPA. The result diverges from your school's number. Four reasons:
- A+ ceiling differences. Your school caps A+ at 4.0. LSAC uses 4.33.
- Repeat handling. Your school replaces the lower grade. AMCAS counts both.
- Course classification. AMCAS may move a course between BCPM and All Other.
- Excluded marks. Your school might count a pass-fail course toward GPA. The service might not.
See AMCAS BCPM Explained for the deep dive on med-school recalculation.
Sources
- Wikipedia: Academic grading in the United States
- AAMC: Grades and GPA Calculations
- UC: GPA Requirement
Related calculators
- GPA Calculator (universal), standard 4.0 with plus-minus
- Cumulative GPA, roll up every semester
- Weighted GPA, honors and AP/IB bonuses
- AMCAS GPA, med school recalculation