Your GPA appears on every transcript and application you will ever send. Most students know whether theirs is high or low -- but surprisingly few understand exactly how the number is calculated. That matters, because understanding the formula helps you make strategic decisions about your course load, grade recovery, and how to present your record to colleges or employers.
The 4.0 Scale
Most US high schools and colleges convert letter grades to a numeric value on a 4.0 scale:
| Letter Grade | Percentage Range | GPA Points |
|---|---|---|
| A+ | 97-100% | 4.0 (sometimes 4.3) |
| A | 93-96% | 4.0 |
| A- | 90-92% | 3.7 |
| B+ | 87-89% | 3.3 |
| B | 83-86% | 3.0 |
| B- | 80-82% | 2.7 |
| C+ | 77-79% | 2.3 |
| C | 73-76% | 2.0 |
| C- | 70-72% | 1.7 |
| D | 60-69% | 1.0 |
| F | Below 60% | 0.0 |
Some schools use plus/minus variations; others use a simpler A/B/C/D/F scale with no intermediate values. Check your school's grading policy -- the conversion table above is the most common but not universal.
Unweighted GPA
An unweighted GPA treats all courses equally regardless of difficulty. An A in gym class and an A in AP Calculus both contribute 4.0 points. The calculation is a simple average of all grade points.
Formula: GPA = Sum of all grade points / Number of courses
Worked example -- a semester with 5 courses:
- English: B+ = 3.3
- US History: A- = 3.7
- Algebra II: B = 3.0
- Chemistry: B+ = 3.3
- Spanish III: A = 4.0
Sum: 3.3 + 3.7 + 3.0 + 3.3 + 4.0 = 17.3. GPA: 17.3 / 5 = 3.46
Weighted GPA
Weighted GPA adds bonus points for honors and AP/IB courses to reward students who take more challenging classes. The most common system:
- Regular course: standard 4.0 scale
- Honors course: add 0.5 points to the grade value
- AP or IB course: add 1.0 point to the grade value
Using the same semester, but assuming History is Honors and Chemistry is AP:
- English: B+ = 3.3
- Honors US History: A- = 3.7 + 0.5 = 4.2
- Algebra II: B = 3.0
- AP Chemistry: B+ = 3.3 + 1.0 = 4.3
- Spanish III: A = 4.0
Sum: 3.3 + 4.2 + 3.0 + 4.3 + 4.0 = 18.8. Weighted GPA: 18.8 / 5 = 3.76
The same grades produce a 3.46 unweighted and a 3.76 weighted. Colleges that review both understand that a 3.5 weighted GPA in a mostly-regular course load is a different record than a 3.5 weighted GPA with six AP courses.
Credit Hours and the College Calculation
College GPA almost always weights grades by the number of credit hours a course carries. A 4-credit course counts more toward your GPA than a 1-credit lab or seminar. The formula shifts from a simple average to a weighted average:
GPA = Sum of (Grade Points x Credit Hours) / Total Credit Hours
Example: A (4.0) in a 4-credit course, B (3.0) in a 3-credit course, and C (2.0) in a 2-credit course.
- (4.0 x 4) + (3.0 x 3) + (2.0 x 2) = 16 + 9 + 4 = 29
- Total credits: 4 + 3 + 2 = 9
- GPA: 29 / 9 = 3.22
This is why a strong grade in a 4-credit lecture course helps your GPA more than a strong grade in a 1-credit elective.
Semester vs. Cumulative GPA
Your semester GPA reflects only the current term. Your cumulative GPA is the weighted average across every course you have ever taken. A single good or bad semester has a diminishing effect on cumulative GPA the further you progress -- because each semester's grades carry less weight in an ever-growing pool.
Practical implication: a 2.8 GPA going into sophomore year can be recovered to a 3.2 by graduation with consistent 3.5+ semesters. The math works in your favor as the number of total credits grows. Our Grade Calculator can show you what GPA you need in future semesters to hit a target cumulative GPA.