What Do I Need on My Final
To find the score you need on a final exam to reach a target course grade:
To find the score you need on a final exam to reach a target course grade:
Needed final score = (Target grade − Current grade × (1 − w)) ÷ w
Here w is the final exam's weight as a decimal (25% = 0.25), and "current grade" is your grade on everything except the final.
Example: your current grade is 84%, the final is worth 25%, and you want an 85% in the course. Needed score = (85 − 84 × 0.75) ÷ 0.25 = (85 − 63) ÷ 0.25 = 88%.
Why the formula works
Your course grade is a weighted average of two parts: everything before the final, and the final itself.
Course grade = Current × (1 − w) + Final × w
With an 84% current grade and a 25% final, the work you have already done is locked in at 84 × 0.75 = 63 points of the course grade. The final can add up to 25 more. Solving for the final score gives the formula above. Check the example: 63 + 88 × 0.25 = 63 + 22 = 85. ✔
This is the same weighted-average idea behind course grades in general, explained in how to calculate a weighted grade.
Different targets, same starting point
| Target course grade | Score needed on the final |
|---|---|
| 80% | 68% |
| 85% | 88% |
| 90% | 108% |
Each 1-point increase in the target needs 4 more points on the final, because the final is worth a quarter of the grade (1 ÷ 0.25 = 4). The heavier the final, the less each point on it costs you.
When the answer is above 100%
A result of 108% means the target is out of reach on the final alone: even a perfect score gives 63 + 25 = 88%. That is still useful to know. It tells you the realistic ceiling (88%) and that a 90% would need extra credit, a curve, or a policy such as dropping a low score.
The opposite case matters too. If the formula gives a negative number or a very low score, your target is already safe. The worst-case grade is simply your current grade times (1 − w): here, 84 × 0.75 = 63% if you scored zero on the final.
Another example: a heavier final
Current grade 78%, final worth 40%, target 80%:
(80 − 78 × 0.60) ÷ 0.40 = (80 − 46.8) ÷ 0.40 = 83%
With a 40% final, your current grade matters less and the exam matters more, so moving from 78 to 80 needs only a solid 83 on the final.
Check these before you trust the number
- Is your "current grade" really everything except the final? If some assignments are not graded yet, the true current grade, and the weight left, are different. The Required Grade Calculator takes the weight already completed and the weight still remaining, so it covers that case. Treat all the remaining work as one block and it tells you the average you need across it.
- Does your course use points instead of percentages? In a points-based course, the final's weight is its points divided by the total points.
- Are there special rules? Some courses replace a low exam with the final score, or require a minimum score on the final to pass regardless of the average.
- What grade cutoffs apply? An 89.5% might round to an A− in one course and not in another. Your syllabus is the authority.
Once you know your course grade, you can see how it affects your overall average in how to calculate unweighted GPA.
Using the Final Grade Calculator
Enter your current grade, the final exam's weight and your target in the Final Grade Calculator. It shows the score you need, how much your existing work already contributes, and whether the target is achievable. For 84%, a 25% final and an 85% target it returns 88%. For a 90% target it returns 108% and flags that the target needs more than 100% on the final.