How do I calculate my overall grade?
Last updated March 26, 2026
Multiply each assignment score by its weight percentage, add them together, then divide by the total weight. If homework (20%) is 92 and midterm (30%) is 85, your weighted average so far is (92×20 + 85×30) / 50 = 87.8%.
How to Calculate
- 1
List all assignments with their scores and weights (percentage of final grade)
- 2
Multiply each score by its weight
- 3
Add up all the weighted scores
- 4
Divide by the total weight to get your weighted average
The Formula
Grade = Σ(Score_i × Weight_i) / Σ(Weight_i)For each assignment, multiply the score by the weight (as a percentage of the final grade). Sum all weighted scores, then divide by the sum of all weights. If all weights add up to 100, dividing by 100 gives your final grade directly.
| Variable | Meaning |
|---|---|
| Score_i | Your score on assignment i (as a percentage, e.g., 92 for 92%) |
| Weight_i | The weight of assignment i as a percentage of the final grade (e.g., 20 for 20%) |
Common Examples
Homework 92% (20%), Midterm 85% (30%)
87.8% (so far)
Homework 88% (20%), Midterm 76% (30%), Final 82% (50%)
81.4%
Need on final: have 85% on 70% of work, need 80% overall
68.3% needed on remaining 30%
Need on final: have 78% on 60% of work, need 90% overall
108% needed (impossible!)
5 equal-weight tests: 88, 92, 76, 95, 84
87% average
Curved: class average 72, your score 85, curve adds 8 points
93%
How Weighted Grades Work
Most courses don't treat every assignment equally. A final exam worth 50% of your grade matters far more than a homework set worth 5%. Weighted grading reflects this by multiplying each score by how much it counts toward your final grade.
For example, suppose your syllabus breaks down like this: homework 20%, midterm 30%, final exam 50%. If you scored 88% on homework and 76% on the midterm, your grade so far is (88×20 + 76×30) / (20+30) = (1,760 + 2,280) / 50 = 80.8%. The final exam hasn't happened yet, so you divide by 50 (the total weight completed), not 100.
Once all assignments are in, the total weight should equal 100, and your weighted average is simply the sum of all (score × weight) divided by 100.
Letter Grade Scale Reference
While grading scales vary by institution, the most common scale used in the United States is:
- A (90–100%) — Excellent. GPA equivalent: 4.0 (A+ and A), 3.7 (A−)
- B (80–89%) — Above average. GPA equivalent: 3.3 (B+), 3.0 (B), 2.7 (B−)
- C (70–79%) — Average. GPA equivalent: 2.3 (C+), 2.0 (C), 1.7 (C−)
- D (60–69%) — Below average. GPA equivalent: 1.3 (D+), 1.0 (D), 0.7 (D−)
- F (below 60%) — Failing. GPA equivalent: 0.0
Some schools use plus/minus grading within each letter (e.g., B+ = 87–89, B = 83–86, B− = 80–82), while others use straight letter grades with no plus or minus. Always check your institution's specific scale.
GPA Conversion
Your Grade Point Average (GPA) is calculated similarly to a weighted grade, but using grade points instead of percentages. Each letter grade maps to a point value on a 4.0 scale. To calculate your GPA, multiply each course's grade points by its credit hours, sum the results, and divide by total credit hours.
For example, if you earned an A (4.0) in a 3-credit course and a B+ (3.3) in a 4-credit course, your GPA = (4.0×3 + 3.3×4) / (3+4) = (12.0 + 13.2) / 7 = 3.6. A 3.5 GPA falls between a B+ and an A− and is generally considered strong for graduate school applications.
What Do I Need on the Final?
This is one of the most common grade questions students ask. The formula is straightforward:
Required Score = (Target Grade × 100 − Current Grade × Completed Weight) / Remaining Weight
If you have an 85% on 70% of the coursework and need an 80% overall, the final exam (worth 30%) requires: (80×100 − 85×70) / 30 = (8,000 − 5,950) / 30 = 68.3%. That's a relief — you only need a 68.3% on the final to hit your target.
But if your target is higher, the math can get harsh. With a 78% on 60% of the work and a target of 90% overall, you'd need: (90×100 − 78×60) / 40 = (9,000 − 4,680) / 40 = 108%. Since you can't score above 100% on a standard exam, a 90% is mathematically impossible in this scenario. Knowing this early lets you adjust your expectations or focus on extra credit if available.
Dropped Lowest Grades
Many professors drop the lowest quiz or homework score. To calculate your grade with a dropped score, remove the lowest score from the set, then calculate the weighted average on the remaining scores. If you have five equally weighted quizzes (88, 92, 76, 95, 84) and the lowest is dropped, remove the 76 and average the remaining four: (88 + 92 + 95 + 84) / 4 = 89.75%. Without the drop, the average would be 87%. Dropping the lowest score raised the grade by nearly 3 points.
When assignments have different weights, dropping the lowest becomes more nuanced — you drop the one that hurts your average the most, which isn't always the lowest raw score. A 70% on a 5% assignment hurts less than an 80% on a 25% assignment if the 80% is below your current average.
Extra Credit Impact
Extra credit adds points to your numerator without changing the denominator. If your weighted total is 81.4 out of 100 and you earn 3 extra credit points, your grade becomes 84.4%. The impact depends on how many extra credit points are available relative to the total. In a course worth 1,000 total points, 20 extra credit points can raise your grade by 2 percentage points — which could be the difference between a B− and a B.
Some professors add extra credit as a percentage bonus to a specific assignment, while others add flat points to your overall total. Always clarify how extra credit is applied so you can accurately calculate its effect on your final grade.