Weight each piece, then add
A semester grade is a weighted average: multiply each quarter and the final by its share, then sum. The weights must add up to 100%. The common 40-40-20 split makes the two quarters count for most of the grade.
- Example. Q1 = 90, Q2 = 82, final = 78, weights 35-35-30 → 31.5 + 28.7 + 23.4 = 83.6, a solid B.
Common weighting schemes
| Scheme | Q1 | Q2 | Final |
|---|---|---|---|
| Balanced | 40% | 40% | 20% |
| Exam-heavy | 30% | 30% | 40% |
| Even thirds | 33% | 33% | 34% |
| No final | 50% | 50% | 0% |
The higher the final's weight, the more one exam can move your grade — up or down. Always confirm the split from your own syllabus.
Working out the score you need
To find the final-exam score for a target semester grade, back out the quarters you already have. If the answer comes out above 100, the target is not reachable with that exam weight.
- Q1 = 85, Q2 = 88, target = 87 under 40-40-20 → (87 − 34 − 35.2) ÷ 0.20 = 89 needed on the final.
Common questions
How is a semester grade calculated?
Each quarter and the final exam is multiplied by its weight, then the pieces are added. Under a common 40-40-20 scheme, a semester grade is Quarter 1 times 0.40 plus Quarter 2 times 0.40 plus the final times 0.20.
What grade do I need on the final to pass?
Take your target semester grade, subtract each quarter times its weight, and divide by the final's weight. If the result is above 100, the target is out of reach with that exam weight.
Do the weights have to add up to 100%?
Yes. The quarter and final weights together must total 100% (1.0 as fractions), otherwise the weighted average is distorted. Check your syllabus for the exact split your course uses.
