How to Calculate the Final Exam Score You Need
As the semester comes to a close, the most common question students ask is: "What do I need to get on the final to pass the class?" This calculator uses a simple algebraic formula to determine exactly what percentage you need to score on your final exam to achieve your target grade.
The Final Grade Formula
Required Final Score = (Target Grade - (Current Grade × (1 - Final Exam Weight))) ÷ Final Exam Weight
Example: Current Grade 85%, Target Grade 90%, Final Exam Weight 20%.
- Weight of current grade: 100% - 20% = 80%
- Current grade × its weight: 85 × 0.80 = 68
- Subtract from target: 90 - 68 = 22
- Divide by final weight: 22 ÷ 0.20 = 110%
In this scenario, you would need a 110% on the final exam — mathematically impossible without extra credit.
Frequently Asked Questions
What if the calculator says I need over 100%?
It means it is mathematically impossible to achieve your target grade based on the weight of the final exam, unless your professor offers significant extra credit.
What if the calculator says I need a negative number?
Congratulations. You have already secured your target grade. Even if you score a zero on the final exam, your overall class grade will not drop below your target.
Does this work if my final is based on points instead of a percentage?
If your class uses a strict point system, subtract your current total points from the points required for your target grade. For example, if you need 450 points for an A and currently have 360 points, you need 90 points on the final exam.
How to Read the Result
A result between 0% and 100% means the target is mathematically possible under the weights entered. A result above 100% means the target requires extra credit or a grading change. A negative result means your current grade is already high enough that the target is protected even with a very low final exam score.
Final Exam Weight vs. Final Exam Points
Some syllabi say the final exam is worth a percentage of the course, such as 20%. Other classes use total points, such as 100 points out of 500. If the class uses points, convert the final into a weight by dividing final exam points by total course points.
Before You Rely on the Number
- Confirm whether your current grade includes every assignment so far.
- Check whether the final replaces a low exam score.
- Look for dropped quizzes, extra credit, curves, or participation rules.
- Use the scenario table to compare realistic final exam scores.
- Ask your instructor if the syllabus and gradebook disagree.