Final Grade Calculator
What score you need on the final exam to reach your target course grade.
What it does
Course grades are weighted averages. Everything done so far holds one share of the total, and the final holds the rest. The score you need on the final is whatever closes the gap between your current average and your target, scaled by the final weight.
The tool above solves that in one step. Enter your current average, the final share of the course, and the grade you want. It returns the exact final score needed and says plainly whether the target is reachable.
Small weights forgive a lot. With a 20% final, each point you need above your average costs five final points. That is why the same target can look easy in one syllabus and brutal in another.
How to use
- Enter your current course average without the final.
- Enter the final weight exactly as the syllabus states it.
- Enter the course grade you want to finish with.
- Read the needed score. Above 100% means the target is out of reach; below 0% means it is already locked.
Formula
- current
- Course average before the final, drops applied.
- w
- Final share as a rate. 20% is 0.20.
- wanted
- Target course grade to finish with.
The current average is shrunk to its share first, then the final must supply the rest. Extra credit and dropped scores sit outside this formula, so add them to the current average before calculating.
Worked example
Example: 88% now, 20% final, want 90%
Current 88, final weight 20%, target 90.
- Kept share: 88 x 0.80 = 70.4.
- Gap: 90 - 70.4 = 19.6.
- Divide by final share: 19.6 / 0.20 = 98.0.
- Answer: 98.0% on the final. Hard, but possible.
Reference table
| Final weight | Keep 88% | Reach 90% | Reach 93% |
|---|---|---|---|
| 10% | 79.2 held | 108.0% (out of reach) | 138.0% (out of reach) |
| 20% | 70.4 held | 98.0% | 113.0% (out of reach) |
| 30% | 61.6 held | 94.7% | 104.7% (out of reach) |
| 40% | 52.8 held | 93.0% | 100.5% (about perfect) |
Limits
- Single final assumed. Split finals need weighting first.
- Curves and extra credit sit outside the formula.
- Grade floors and rounding policies vary.
- Syllabus weights beat remembered ones.
Common mistakes
- Entering the final weight as points instead of percent of the course.
- Leaving dropped quizzes in the current average when the syllabus drops them.
- Forgetting curves or extra credit that shift the current average first.
- Rounding the current average up before calculating, which hides a point or two.
- Chasing an impossible target instead of protecting the next grade down.
Try it yourself
Quick checks. Answers sit tucked under each question.
70 now, 30% final, want 75?
(75 - 70 x 0.70) / 0.30 = 86.7% needed.
95 now, 20% final, want 90?
(90 - 95 x 0.80) / 0.20 = 70.0% needed.
Questions
What if I need over 100%?
The target is out of reach under the stated weights. Aim one grade lower or ask about extra credit.
What if the answer is negative?
The target is already secured even at zero on the final. Still show up, but the pressure is off.
How do dropped scores fit in?
Remove them from the current average first, then run the tool. The formula only sees the average you enter.
Does extra credit change the math?
Yes. Add it to the current average (capped per syllabus rules) before calculating.
Why does weight matter so much?
The final must cover the whole gap through its small share. Double the weight roughly halves the needed score above your average.