What do you need on the final exam to get the grade you want?
| Current Grade | Final Worth 10% | Final Worth 20% | Final Worth 30% |
|---|---|---|---|
| 60% | 360% ✗ | 210% ✗ | 160% ✗ |
| 70% | 270% ✗ | 170% ✗ | 136.7% ✗ |
| 80% | 180% ✗ | 130% ✗ | 113.3% ✗ |
| 85% | 135% ✗ | 110% ✗ | 101.7% ✗ |
| 90% | 90% ✓ | 90% ✓ | 90% ✓ |
A hard truth in one table: to lock an A before the final, you already need a 90. An 85 with a 30% final needs 101.7 on the exam — close, but out of reach in most classes. Check the syllabus for the real weight; finals run anywhere from 10% to 40%.
| Current Grade | B: Final Worth 20% | B: Final Worth 30% | C: Final Worth 20% | C: Final Worth 30% |
|---|---|---|---|---|
| 50% | 200% ✗ | 150% ✗ | 150% ✗ | 116.7% ✗ |
| 60% | 160% ✗ | 126.7% ✗ | 110% ✗ | 93.3% ✓ |
| 70% | 120% ✗ | 103.3% ✗ | 70% ✓ | 70% ✓ |
| 75% | 100% ✓ | 91.7% ✓ | 50% ✓ | 58.3% ✓ |
Read the B columns as the price of a slow semester: at 70% going in, a 20% final still demands a 120 to reach the B. The C columns show the rescue math — 60% going in needs a 93.3 when the final counts 30%.
Your course grade has two parts: everything before the final, worth (100% − final weight), and the final itself. Course grade = current × (1 − w) + final × w. Flip that around to solve for the final score you need: needed = (target − current × (1 − w)) ÷ w.
Open the gradebook, type in your current grade, and copy the final's weight from the syllabus (it's usually stated as "the final exam counts 20% of your grade"). Set the target to the letter cutoff you're chasing — 90 for an A, 80 for a B, 70 to pass in most classes. The three small result tiles show your course grade if you ace it (100), do average (70), or bomb it (0), which frames the range before you study a single hour.
You're at 78% and the final is worth 25%. You want the B, so 80%. Current contribution: 78 × 0.75 = 58.5 points. The final must supply 80 − 58.5 = 21.5 of its 25 points, and 21.5 ÷ 0.25 = 86. An 86 on the final gets you exactly the 80.
Second example, the other side of the coin. You're at 85% with a 20% final and want the A (90%). Needed: (90 − 85 × 0.80) ÷ 0.20 = 110. Not happening. Even a perfect exam gives 85 × 0.80 + 100 × 0.20 = 88, a B+. The calculator flags this instead of pretending it's possible, so you aim at the grade that's actually on the table.
Subtract your current grade times its share of the course from your target grade, then divide by the final's weight. If the final is 25% of the grade, your current grade is the other 75%: needed score = (target − current × 0.75) ÷ 0.25. Sitting at 78% and wanting an 80%? (80 − 58.5) ÷ 0.25 = 86. You need an 86 on the final.
Then the target grade is mathematically out of reach. With an 85% current grade and a final worth 20%, even a perfect 100 leaves you at 88%, short of a 90. The calculator tells you the highest grade still possible so you can aim for the letter you can actually get.
You've already locked in the target. If you're at 90% and need a 70 to pass with the final worth 20%, the required score works out to −10% — even a zero on the final leaves you at 72%. A strong final still matters for borderline cases, but the target itself is safe.
Yes — homework, quizzes, midterms, labs, participation, all of it. Your current grade is whatever the gradebook shows going into the final, and the final's weight is whatever's left. If your course weights categories instead (homework 20%, midterms 30%, final 50%), compute the weighted current grade first, then run the same formula.
Set the target to your class's passing line — usually 60% or 70%. At a 70% pass line with a 30% final, a student at 60% needs a 93.3, and a student at 65% needs an 81.7. At a 60% pass line, someone at 50% with a 30% final needs an 83.3. The gap closes fast as the final gets heavier.
Multiply your current grade by one minus the final's weight. An 85% average with a 20% final drops to 68% (85 × 0.80), usually a D+. A 78% average with a 25% final drops to 58.5%, failing. The what-if mode runs this math for any exam score you enter.