How to use the final grade calculator
- Enter your current grade in the class as a percentage. Your online gradebook usually shows it.
- Enter the grade you want to finish with, for example 90 for an A− or 80 for a B−.
- Enter how much the final exam counts toward your grade. You'll find it in the syllabus.
- The calculator shows the minimum score you need on the final, plus what it takes to reach each letter grade.
The final exam grade formula
Your final course grade is a mix of your current grade and your final exam score, weighted by how much the final counts. Solving that for the exam score gives the formula this calculator uses:
If the answer is above 100%, the target is out of reach without extra credit. If it is zero or below, you have already secured that grade.
Worked example
Current grade 88%, target 90%, final worth 25%.
(90 − 88 × 0.75) ÷ 0.25 = (90 − 66) ÷ 0.25 = 96% needed on the final.
A perfect 100% would give this student a 91%. A zero would drop the class to 66%, which shows how much a heavily weighted final matters.
Why the final's weight changes everything
The more a final is worth, the more it can move your grade in either direction. Here is what a student with an 85% needs to reach a 90% at different final exam weights:
| Final exam weight | Score needed for 90% |
|---|---|
| 10% | 135.0% (not possible) |
| 20% | 110.0% (not possible) |
| 30% | 101.7% (not possible) |
| 40% | 97.5% |
| 50% | 95.0% |
With a small final, jumping a full letter grade is often impossible. With a large final, it is realistic, but a bad exam day costs more too.
How to prepare once you know your number
- Start from the target score. If you need 75%, focus on securing the core material rather than chasing every hard question.
- If the number is above 100%, ask your teacher about extra credit or whether the final can replace a low test score.
- Check your current grade with the weighted grade calculator if your gradebook isn't up to date.
Frequently asked questions
How do I calculate what I need on my final?
Subtract your current grade multiplied by (1 minus the final's weight) from your target grade, then divide by the final's weight. For example, with an 88%, a 90% target and a final worth 25%: (90 − 88 × 0.75) ÷ 0.25 = 96%.
What if the calculator says I need more than 100%?
Your target is not reachable with the final alone. A perfect score would still leave you short. Ask about extra credit, or set your target to the next grade down to see what you need for it.
What if my final is worth points instead of a percentage?
Divide the final's points by the total points in the course and multiply by 100. A 200-point final in a 1,000-point course is worth 20%.
Can I fail the final and still pass the class?
Often, yes. The stats panel shows your grade if you score 0% on the final. If that is still 60% or higher, you would pass on the standard scale. Some schools require a minimum exam score, so check your syllabus.
Does this work for college and high school?
Yes. The formula is the same for any class where the final exam is a fixed percentage of the grade.