Final Grade Calculator
What you need on the final exam to get the grade you want.
Good to know. The bigger the final’s weight, the more a good exam can rescue. Or the other thing.
How it works
In plain words
Your final grade is your grade so far, weighted by everything except the final, plus the final score weighted by the final’s share. Solve that for the final score.
The formula
grade = current × (1 − w) + final × w needed on final = (target − current × (1 − w)) ÷ w
Worked example
With 84% so far and a final worth 30%, reaching 90% needs (90 − 84 × 0.7) ÷ 0.3 = (90 − 58.8) ÷ 0.3 = 104%. Out of reach without extra credit.
Sources
No outside data or rates: this is plain arithmetic.
4 automated tests check its answers on every change.
About the final grade calculator
Near the end of a course, the question is usually not “what is my grade?” but “what do I need on the final?”. This calculator answers it from three numbers: your grade so far, how much the final exam counts, and the grade you are aiming for.
The logic is simple. If the final is worth 30%, everything you have done so far counts for the other 70%. An 84% so far therefore contributes 58.8 points to the final grade, and the exam has to supply the rest of the 90 you want: 31.2 points, which is 104% of the 30 available. That target is out of reach, but 85% would need only 87.3% on the final.
The calculator also shows the range you can still land in: your grade with a zero on the final and with a perfect score. Anything you want between those two is possible; anything outside it is not.
Use your current grade as your teacher calculates it, which is usually a weighted average of categories like homework, quizzes and tests. If you don’t have it, the weighted average calculator can work it out from your scores and their weights. Rounding rules, curves and minimum-score requirements vary between courses, so check your syllabus.
Questions people ask
How do I calculate what I need on my final?
(target − current × (1 − w)) ÷ w, where w is the final’s weight as a decimal. With 84% so far, a final worth 30% and a target of 85%: (85 − 58.8) ÷ 0.3 = 87.3%.
What if the answer is over 100%?
Then the target can’t be reached with the final alone, unless the exam has extra credit. Try a lower target.
What if the answer is negative?
You will reach the target even with a zero on the final.