The relationship between your percentage scores, letter grades, and GPA points can feel opaque -- especially when different schools and different instructors use slightly different scales. This guide explains how all three systems relate to each other, how to calculate your grade from multiple assignments, and what you need to score to hit a specific target.
Grade Percentage to Letter Grade to GPA
| Percentage | Letter Grade | GPA Points (4.0 Scale) |
|---|---|---|
| 97-100% | A+ | 4.0 |
| 93-96% | 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 |
Always check your specific school or course syllabus -- scales can vary. Some professors use a 7-point scale (90-100 = A, 80-89 = B, etc.) while others use the 10-point scale above.
How to Calculate Your Grade from Multiple Assignments
The basic method: add up all points earned across every graded item, then divide by total points possible.
Example: Quiz 1: 18/20. Test: 82/100. Homework: 47/50. Project: 88/100. Total earned: 18+82+47+88 = 235 points. Total possible: 20+100+50+100 = 270 points. Grade: (235/270) x 100 = 87%. That's a B+.
Weighted Grades
Many courses assign different weights to different categories of work. Your syllabus might say: Tests = 40%, Projects = 35%, Homework = 25%. To calculate your overall grade when weights are specified, multiply each category average by its weight and add the results.
Example: Tests average 78%, Projects average 91%, Homework average 95%.
Weighted grade = (0.40 x 78) + (0.35 x 91) + (0.25 x 95) = 31.2 + 31.85 + 23.75 = 86.8%. That rounds to a B.
Notice how a strong homework grade (95%) doesn't move the needle as much as the test grade does, because tests carry the highest weight. Knowing the weights helps you decide where to focus your effort.
How to Calculate What You Need on a Final Exam
If you know your current grade and the weight of the final exam, you can work out the minimum score needed to achieve a target overall grade.
Formula: Minimum final score = (Target grade - (Current grade x (1 - Final weight))) / Final weight
Example: You have an 82% going into a final exam worth 30% of your grade, and you want an 85% overall.
Minimum final = (0.85 - (0.82 x 0.70)) / 0.30 = (0.85 - 0.574) / 0.30 = 0.276 / 0.30 = 92%. You need a 92% on the final to pull your grade to 85%.
GPA Calculation Across Multiple Courses
Your cumulative GPA is a weighted average of your letter grade GPA points, weighted by the number of credit hours each course carries.
Example: English (3 credits, B = 3.0), Math (4 credits, A- = 3.7), History (3 credits, B+ = 3.3). Total quality points = (3 x 3.0) + (4 x 3.7) + (3 x 3.3) = 9.0 + 14.8 + 9.9 = 33.7. Total credit hours = 3+4+3 = 10. GPA = 33.7 / 10 = 3.37.
Extra Credit Math
Extra credit adds to your points earned without changing the total possible points. This can raise your percentage significantly because it increases your numerator without touching the denominator. Example: You earned 88 out of 100 points (88%). With 5 extra credit points: 93/100 = 93%. The extra credit moved you from a B+ to an A-.
Unweighted vs. Weighted GPA
An unweighted GPA caps at 4.0 and treats all courses equally. A weighted GPA (used by many high schools) awards extra GPA points for Honors, AP, or IB courses -- typically 4.5 or 5.0 for an A in those courses. When comparing GPAs between students or schools, always clarify whether the figure is weighted or unweighted. Use our Grade Calculator to find your current grade or the score you need on an upcoming exam.