How to use the final grade calculator
- Current grade — your grade in the class right now, covering everything except the final. Most class portals show it.
- Final exam weight — the share of the overall grade the final is worth, listed in the syllabus (for example 20%, 25% or 30%).
- Overall grade you want — the course grade you are aiming for, such as 90% for an A.
The formula
Your overall grade is a weighted average of your current grade and your final exam score:
Overall = current × (1 − w) + final × w
where w is the final's weight as a decimal. Solving for the final exam score gives:
Needed on final = (desired − current × (1 − w)) ÷ w
Worked example
You have an 84% going into the final, the final is worth 30% and you want an 85% overall. Your current work counts for 70% of the grade: 84 × 0.70 = 58.8 points locked in. You need 85 − 58.8 = 26.2 more points from the final, which is worth 30 points, so you need 26.2 ÷ 0.30 = 87.33% on the exam.
Here is how different exam scores would play out for that student:
| Final exam score | Overall grade |
|---|---|
| 60% | 76.8% |
| 70% | 79.8% |
| 80% | 82.8% |
| 90% | 85.8% |
| 100% | 88.8% |
When the answer is over 100% or below 0%
- Above 100% means the target can't be reached with the final alone. With a 70% current grade and a 25% final, even a perfect exam only reaches 77.5% — an 80% would need 110%. Ask whether extra credit or a dropped low score is available, or set a realistic target.
- Zero or below means you have already locked in the grade: even a 0 on the final would keep you at or above your target. You still want to take the exam — a 0 would drag your grade down and many courses require a passing final.
Tips for getting the inputs right
- Use the weighted current grade. If your class weights homework, quizzes and tests differently, your current grade is the weighted average, not a simple average of your scores. The number in your class portal usually already accounts for this.
- Check for points-based grading. If the course adds up points instead of using weights, the final's weight is its points divided by the total points in the course.
- Watch for special rules. Some courses let the final replace your lowest test or require a minimum exam score to pass. Those rules override this formula.
- Know the letter cutoffs. Find out whether your teacher rounds — 89.5% may or may not count as an A.
Once you know your course grades, the GPA calculator shows what they do to your GPA.
Frequently asked questions
What score do I need on my final to get an A?
Enter 90 (or your class’s A cutoff) as the overall grade you want. With an 85% current grade and a 20% final, you need (90 − 85 × 0.8) ÷ 0.2 = 110%, so an A is out of reach; with a 40% final you would need 97.5%.
How much will my final exam affect my grade?
Exactly as much as its weight. A final worth 25% can move your overall grade by up to 25 points relative to your current grade — the table under the result shows the overall grade for a range of exam scores.
What if my current grade already includes the final weight?
Enter the grade you have on the work completed so far, not a grade that treats the final as a zero. If your portal shows a lower number because it counts the missing exam as 0, ask your teacher for the grade on completed work.
Can I use this for a midterm or any other exam?
Yes. Enter your current grade, the weight of the upcoming exam or project and your target — the formula is the same for any single remaining assignment.
Last updated: October 8, 2026