Percentage Grades, Letter Grades and GPA: How They Convert
How percentages become letter grades and GPA points on a 4.0 scale, how plus/minus grades and weighted GPAs work, and how one final exam affects your GPA.
Your course grade usually starts as a percentage, becomes a letter on your report card, and finally a number of grade points in your GPA. Each step involves a conversion that varies by school, so always check your school's handbook, but the common scales below cover most US high schools and colleges.
Common percentage-to-letter scale
| Percentage | Letter | GPA points (4.0 scale) |
|---|---|---|
| 93–100 | A | 4.0 |
| 90–92 | A− | 3.7 |
| 87–89 | B+ | 3.3 |
| 83–86 | B | 3.0 |
| 80–82 | B− | 2.7 |
| 77–79 | C+ | 2.3 |
| 73–76 | C | 2.0 |
| 70–72 | C− | 1.7 |
| 67–69 | D+ | 1.3 |
| 63–66 | D | 1.0 |
| 60–62 | D− | 0.7 |
| below 60 | F | 0.0 |
Many schools use a simpler scale without plus or minus: 90+ = A (4.0), 80–89 = B (3.0), 70–79 = C (2.0), 60–69 = D (1.0). That's the scale used in the table of the final grade calculator; enter your school's exact cutoff as the target if it differs.
How GPA is calculated
GPA is a weighted average of grade points, weighted by credit hours:
GPA = Σ (grade points × credits) ÷ Σ credits
Example semester: A (4.0) in a 4-credit course, B+ (3.3) in a 3-credit course, B (3.0) in a 3-credit course, A− (3.7) in a 1-credit lab. Total points = 16 + 9.9 + 9 + 3.7 = 38.6, total credits = 11, GPA = 3.51.
Weighted GPA
Many high schools give extra points for honors, AP or IB courses, often +0.5 for honors and +1.0 for AP, so an A in an AP course counts as 5.0 on a weighted scale. Colleges often recalculate GPA using their own method, so report both weighted and unweighted GPA when asked. AP exam results are separate from your class grade; you can estimate those with the AP Lang and APUSH score calculators.
How much can one final change your GPA?
Only through the course letter grade. If your final moves you from a B (3.0) to a B+ (3.3) in a 3-credit course, your semester grade points rise by 0.9. Across 15 credits, that raises the semester GPA by 0.06. Small, but it adds up across several courses, and crossing letter boundaries is what matters, which is why the calculator shows the score needed for each letter.
Rounding
Whether an 89.5% becomes a B+ or an A− depends entirely on your instructor's policy. Some round to the nearest whole number, some truncate. See grade rounding and extra credit.
Further reading from official sources
- Weighted averages explained – Khan Academy
