Letter grades and the 4.0 scale
The table below shows the letter-grade conversion most commonly used by US colleges and universities. Individual institutions may differ — some award 4.3 for an A+, others do not use plus/minus grades.
| Letter grade | Grade points (common US convention) |
|---|---|
| A / A+ | 4.0 |
| A- | 3.7 |
| B+ | 3.3 |
| B | 3.0 |
| B- | 2.7 |
| C+ | 2.3 |
| C | 2.0 |
| D | 1.0 |
| F | 0.0 |
- Grading scales are set by each institution: 4.3 scales, no-minus systems, weighted high-school GPAs (5.0 for honors/AP) and percentage conversions all exist. The official registrar's table takes precedence over any generic conversion.
- Pass/fail courses, withdrawals and transfer credits are handled differently across institutions and are often excluded from GPA; check the applicable academic policy.
- A GPA describes coursework performance under one institution's rules. Comparing GPAs across institutions or countries without their conversion policies is unreliable, and this calculator makes no judgment about what any GPA means for admissions.
What is a GPA?
A grade point average summarizes academic performance as a single number: each course grade is converted to grade points, weighted by the course's credit hours, and averaged. Under the standard US 4.0 convention, an A is worth 4.0 points, a B 3.0, a C 2.0, a D 1.0 and an F 0. Plus and minus modifiers commonly adjust by about a third of a point: A- = 3.7, B+ = 3.3, B- = 2.7, C+ = 2.3.
Credit weighting is the essential feature: a 4-credit course influences the GPA more than a 2-credit course with the same grade. The products of grade points and credits are called quality points, and the GPA is total quality points divided by total credits attempted. This is why one poor grade in a high-credit course moves the GPA more than the same grade in a low-credit seminar.
Grading scales vary by institution and country. Some universities use a 4.3 scale that awards 4.3 for an A+, others cap A+ at 4.0, some do not use plus/minus grading at all, and high schools may add weight for honors or AP courses (weighted GPA on a 5.0 scale). Percentage-based systems, common outside the US, convert to grade points differently at each institution. Always check the official conversion table published by the institution whose GPA you are computing.
How to use this GPA calculator
- Convert each course grade to grade points using your institution's scale — under the common US convention: A = 4.0, A- = 3.7, B+ = 3.3, B = 3.0, B- = 2.7, C+ = 2.3, C = 2.0, D = 1.0, F = 0.
- Enter the grade points as a comma-separated list, for example: 4.0, 3.7, 3.3, 4.0, 2.7.
- Enter the credits for the same courses, in the same order, for example: 3, 4, 3, 2, 3. The two lists must have the same number of entries.
- Read your GPA, the total credits, and the quality points (the credit-weighted grade total).
The GPA formula
GPA equals the sum of (grade points x credits) across all courses, divided by the sum of credits. The numerator is the quality points total.
Worked example: grades 4.0, 3.7, 3.3, 4.0, 2.7 with credits 3, 4, 3, 2, 3. Quality points: 4.0 x 3 = 12.0; 3.7 x 4 = 14.8; 3.3 x 3 = 9.9; 4.0 x 2 = 8.0; 2.7 x 3 = 8.1. Total: 12.0 + 14.8 + 9.9 + 8.0 + 8.1 = 52.8. Total credits: 3 + 4 + 3 + 2 + 3 = 15. GPA = 52.8 / 15 = 3.52.
A cumulative GPA applies the same formula across all terms: divide lifetime quality points by lifetime credits. Because it is credit-weighted, a cumulative GPA is not the simple average of term GPAs unless every term carries identical credits.
Common mistakes
- Averaging grades without credit weights: a plain average of 4.0, 3.7, 3.3, 4.0, 2.7 is 3.54, but the credit-weighted GPA of the worked example is 3.52.
- Entering grades and credits in mismatched order — each grade must line up with the credits of the same course.
- Averaging term GPAs to get a cumulative GPA; unless every term has identical credits, cumulative GPA must be recomputed from total quality points and total credits.
- Applying the common US conversion at an institution with a different scale (4.3 for A+, no minus grades, or percentage-based conversion).
- Including pass/fail or withdrawn courses that the institution excludes from GPA calculation.
Câu hỏi thường gặp
How do I calculate my GPA?
Convert each grade to grade points (A = 4.0, B = 3.0, and so on per your institution's scale), multiply each by the course credits to get quality points, add the quality points, and divide by the total credits. For example, 52.8 quality points over 15 credits gives a GPA of 3.52.
What are quality points?
Quality points are the product of a course's grade points and its credit hours — an A (4.0) in a 3-credit course earns 12 quality points. GPA is total quality points divided by total credits, so quality points are the credit-weighted contribution of each course to the average.
What is the difference between weighted and unweighted GPA?
An unweighted GPA uses the standard 4.0 maximum for every course. A weighted GPA, common in US high schools, adds extra points for more rigorous courses — often 5.0 for an A in an AP or honors class — so weighted GPAs can exceed 4.0. Colleges typically state which version they consider. Note this is separate from credit weighting, which both versions use.
Do all universities use the same 4.0 scale?
No. The A = 4.0, B = 3.0 mapping with plus/minus steps of roughly 0.3 is the most common US convention, but institutions differ: some award 4.3 for an A+, some do not use plus/minus grades, and universities outside the US often grade on percentages or entirely different scales. Always use the conversion table published by the institution in question.
How is a cumulative GPA different from a semester GPA?
A semester GPA uses only that term's courses; a cumulative GPA divides all quality points earned to date by all credits attempted to date. Because terms carry different credit loads, the cumulative GPA is generally not the average of semester GPAs — it must be recomputed from the running totals.
Can this calculator handle a 4.3 or 5.0 scale?
Yes, within limits: it accepts grade point values from 0 to 5, so you can enter 4.3-scale values (A+ = 4.3) or weighted high-school values (A in an AP course = 5.0) directly. The arithmetic — quality points divided by credits — is the same on every scale; only the conversion from letters to points changes.
Tài liệu tham khảo
- College Board. How to Convert Your GPA to a 4.0 Scale. collegeboard.org.
- Standard US registrar convention: credit-weighted grade point average (quality points / credit hours), as published in university academic catalogs.