What This Calculator Does
The Required Final Exam Percentage Calculator tells you exactly what score you need on your final exam to finish a course with the grade you want. Instead of guessing, you plug in your current grade, your target grade, and how much the final exam counts toward your overall mark — and it solves for the rest.
How to Use It
Enter three values: your current grade (your average so far, as a percentage), your target final grade (the overall course grade you're aiming for), and the final exam weight (the percentage of your total grade the final is worth). The calculator returns the percentage you must earn on the final. If the result is above 100%, your goal isn't reachable on the final alone; if it's zero or negative, you've already locked in your target.
The Formula Explained
Your final course grade is a weighted average: the work done so far counts for (1 − w) of the grade and the final counts for w, where \(w\) is the final's weight as a decimal. Setting that weighted average equal to your target and solving for the final score gives:
$$\text{Needed} = \dfrac{\text{Target} - \text{Current} \times (1 - w)}{w}$$
For example, if the final is worth 30%, then \(w = 0.30\) and your prior work counts for 0.70.
Worked Example
Suppose your current grade is 85%, you want a final grade of 90%, and the final is worth 30% (\(w = 0.30\)). Then: $$\text{Needed} = \dfrac{90 - 85 \times 0.70}{0.30} = \dfrac{90 - 59.5}{0.30} = \dfrac{30.5}{0.30} \approx 101.67\%$$ Because that exceeds 100%, hitting 90% overall isn't possible from the final alone here — you'd need to lower your target or earn extra credit.
FAQ
What if I get a number over 100%? Your target grade can't be reached with the final exam alone given your current standing. Aim for a slightly lower target.
What does the final exam weight mean? It's the share of your total course grade the final exam contributes — e.g. a final worth 30% means it determines 30% of your final mark.
Can the result be negative? Yes. A negative or zero result means even a 0% on the final still meets or exceeds your target — you're already there.
