To calculate GPA, convert each letter grade to grade points (A = 4, B = 3, C = 2, D = 1, F = 0), multiply by each course's credit hours, add those products, and divide by the total credit hours. Three courses — A (3 cr), B (4 cr), C (3 cr) — give (4×3 + 3×4 + 2×3) ÷ 10 = 30 ÷ 10 = 3.0 GPA.
Key takeaways
- GPA = Σ(grade points × credits) ÷ Σcredits.
- Grade points: A = 4, B = 3, C = 2, D = 1, F = 0.
- GPA is credit-weighted — bigger courses count more.
- Straight B's = 3.0 at any credit load.
- Estimates only — some schools use plus/minus points or different scales.
The three-step method
GPA is just a credit-weighted average of grade points. The steps:
The "quality points" in step 2 are the engine — they let a 4-credit course count more than a 1-credit one. The GPA calculator does all three steps; just enter each course's letter and credits.
Worked example: a four-course semester
Suppose you took four courses: Biology (A, 4 cr), History (B, 3 cr), Calculus (B, 4 cr), and Art (A, 1 cr). Convert and weight each:
| Course | Letter | Points | Credits | Quality points |
|---|---|---|---|---|
| Biology | A | 4.0 | 4 | 16.0 |
| History | B | 3.0 | 3 | 9.0 |
| Calculus | B | 3.0 | 4 | 12.0 |
| Art | A | 4.0 | 1 | 4.0 |
| Total | 12 | 41.0 |
Divide total quality points by total credits: 41.0 ÷ 12 = 3.42 GPA. Notice the 1-credit Art A barely nudges the average, while the 4-credit grades dominate — that is the credit weighting at work.
The 4.0 grade-point scale
| Letter | Percentage | Grade points |
|---|---|---|
| A | 90–100% | 4.0 |
| B | 80–89% | 3.0 |
| C | 70–79% | 2.0 |
| D | 60–69% | 1.0 |
| F | Below 60% | 0.0 |
Many schools add plus/minus points (A− = 3.7, B+ = 3.3, and so on). Honors and AP classes may carry bonus points — see the weighted vs unweighted GPA guide. Always confirm your school's exact point values.
Cumulative GPA across terms
Your cumulative GPA uses the same formula across every course you have ever taken — sum all quality points and divide by all credit hours, not by averaging each semester's GPA. The high school GPA calculator rolls multiple semesters into one cumulative number for you.
Frequently asked questions
How is GPA calculated?
Convert each letter to grade points (A=4, B=3, C=2, D=1, F=0), multiply by the course’s credits, sum the products, and divide by total credits: GPA = Σ(points × credits) ÷ Σcredits.
How do credit hours affect GPA?
GPA is a credit-weighted average: a 4-credit course pulls twice as hard as a 2-credit one, because grade points are multiplied by credits before averaging.
What GPA is all B’s?
Straight B’s are a 3.0 GPA at any credit load, since every course contributes 3.0 points per credit.
Sources: the GPA formula (Σ grade points × credits ÷ Σ credits) and the standard 4.0 point scale (A=4 … F=0) reflect common US college and high-school grading practice. Plus/minus point values, weighting for Honors/AP, and inclusion of failed-and-retaken courses vary by institution — confirm with your registrar.
Last reviewed 2026-06-28