What this calculator does
The Final Exam Impact Calculator shows what your overall course grade will be once your final exam is graded. By blending your current grade with your expected final score according to how much the final is worth, it tells you both the projected final grade and how many points the exam shifts your standing — up or down.
How to use it
Enter three numbers: your current grade (the percentage you hold going into the final), your expected final exam score, and the weight of the final exam as a percentage of your total grade (check your syllabus). Press calculate to see your projected course grade and the point impact.
The formula explained
The calculation is a weighted average. If the final is worth w of your grade (as a decimal), then everything else accounts for 1 − w. So:
$$\text{Final Grade} = \text{Current} \times (1 - w) + \text{Final Score} \times w$$
The impact is simply the difference between your projected grade and your current grade.
Worked example
Suppose you have a current grade of 85%, you expect to score 90% on the final, and the final is worth 20% of your grade. Then \(w = 0.20\):
$$\text{Final Grade} = 85 \times 0.80 + 90 \times 0.20 = 68 + 18 = \mathbf{86\%}$$
The final raises your grade by +1 point.
FAQ
What if my current grade already includes the final? It shouldn't. Use the grade from everything except the final exam, and enter the final's weight separately.
Why did a high final barely change my grade? If the final is only worth a small percentage, even a perfect score moves your overall grade only slightly. Increase the weight to see a larger effect.
Can I use this to find the score I need? This tool projects the grade for a given final score. Try different final scores to find the one that reaches your target grade.
