"What do I need on my final?" is the most common grade question of the semester, and it has an exact answer — not a guess. You only need three numbers: your current grade, the grade you want overall, and how much of your course grade the final exam is worth.
The formula
Needed = (Target − Current × (1 − w)) ÷ w
Here, w is the final's weight written as a decimal, so a final worth 30% gives w = 0.30. The logic is simple once you see it: your current grade only applies to the part of the course that is already finished, which is (1 − w) of the total. The rest of your target has to come from the final.
A worked example
Suppose you are on 88%, you want 90% overall, and your final is worth 40% of the grade.
- Current contribution: 88 × (1 − 0.40) = 88 × 0.60 = 52.8
- Still needed: 90 − 52.8 = 37.2
- Divide by the final's weight: 37.2 ÷ 0.40 = 93%
You need 93% on the final. Demanding, but possible — and now you know exactly what you are revising towards.
Where to find the three numbers
Your current grade is in your course portal or gradebook; use the figure before the final is added, not a predicted overall grade. The final's weight is in your syllabus, usually in the grading table on the first pages. Your target is your choice — an A boundary, a scholarship cutoff, or simply the highest grade still reachable.
What the answer can tell you
The result falls into one of three zones. If you need between 0% and 100%, the target is live and the number is your revision goal. If you need 0% or less, your target is already secured — even a zero on the final cannot pull you below it. And if you need more than 100%, that specific target is mathematically gone, no matter how well the exam goes. That is useful information, not bad news to hide from: it lets you redirect effort to the highest grade that is still achievable, or to other courses where revision still moves the outcome.
Points-based courses
If your course counts points instead of percentages, convert first. Your current percentage is points earned ÷ points possible so far. The final's weight is the final's points ÷ total course points. Then the same formula applies — or use points mode on the calculator and let it do the conversion.
Try it yourself
Use the Final Grade Calculator to run your own numbers, then read what to do if you need over 100% if the answer comes back above 100.