How to Calculate Your Grade
Many students are confused by weighted grades. Let's look at a real example using a student named Sarah and her Biology class.
Identify Categories
Sarah's syllabus says: Homework (20%), Quizzes (30%), and Final Exam (50%).
Calculate Points Earned
Multiply her average in each category by the decimal weight (e.g., 20% = 0.20).
Sum the Total
Add the "points earned" together to get the current class grade.
Sarah's Biology Class
Sarah has earned 40.4 out of the 50 possible points available so far.
Grade Scale Reference Chart
Use this chart to convert your percentage into a letter grade or 4.0 GPA scale. Note that some schools use a "Standard" scale (no plus/minus) while others use the specific scale.
| Percent | Letter (Standard) | Letter (+/-) | GPA Point |
|---|---|---|---|
| 97-100% | A | A+ | 4.0 |
| 93-96% | A | A | 4.0 |
| 90-92% | A | A- | 3.7 |
| 87-89% | B | B+ | 3.3 |
| 83-86% | B | B | 3.0 |
| 80-82% | B | B- | 2.7 |
| 77-79% | C | C+ | 2.3 |
| 73-76% | C | C | 2.0 |
| 70-72% | C | C- | 1.7 |
| 60-69% | D | D | 1.0 |
| 0-59% | F | F | 0.0 |
Can I Still Get an A?
The "Optimist" Scenario
Current Grade: 82% (B-)
Final Worth: 30%
To raise an 82% to a 90%, you need a 108% on the final.
The "Too Late" Scenario
Current Grade: 75% (C)
Final Worth: 15%
To get an A (90%), you would need a 175% on the final.
3 Grading Mistakes Students Make
Averaging the Averages
Wrong: (Test 90% + HW 50%) / 2 = 70%.
Right: You must multiply by weight! If Tests are 80% of the grade, the math is (90 × 0.8) + (50 × 0.2) = 82%. That's a huge difference.
Ignoring Empty Categories
If your dashboard says you have a "100%" but you've only done one Homework assignment (worth 10%), you don't really have an A. You have 10 weighted points. The other 90 points are still undecided.
Forgetting "Dropped" Grades
Many teachers drop your lowest quiz score. If you calculate your grade including that "0" you got when you were sick, you might think you're failing when you're actually passing.
Weights ≠ 100%?
If your syllabus weights add up to 85%, the missing 15% is usually your final exam.
If they add up to 105%, your teacher likely built extra credit directly into the category weights.
Extra Credit
Extra credit can be tricky. It usually adds to a specific category, not your final grade directly.
Example: 5 bonus points on a Test (worth 40%) adds 2 points to your final grade (5 × 0.40 = 2).
Grading Systems
- Percentage: Standard 0-100 scale.
- Points: 500/1000 Total Points (Treat as unweighted).
- Standards Based: 1-4 scale (4=Exceeds, 3=Meets).
- Pass/Fail: Usually doesn't affect GPA if Passed.
What to Do If You Are Failing
Don't panic. Follow this 3-step recovery roadmap to salvage your grade.
Final Exam Score "Cheat Sheet"
If you have an 80% (B) right now, here is what you need on the final based on its weight.
| Final Weight | To get an A (90%)... | To keep a B (80%)... | To pass with C (70%)... |
|---|---|---|---|
| 10% | Impossible | 80% | 0% (Secured) |
| 20% | 130% | 80% | 30% |
| 30% | 113% | 80% | 47% |
| 40% | 105% | 80% | 55% |
| 50% | 100% | 80% | 60% |
Grading Terms Glossary
Grade Calculator FAQ
Common questions about calculating weighted grades and finals.