Final grade calculator
Give your current grade, the grade you want and what the final is worth. The score you need comes out.
Enter your current grade, the grade you want and what the final is worth.
How to use it
- Step 1Type the grade you have in the class right now, as a percentage. Your gradebook or the grade calculator on this site will give it to you.
- Step 2Type the grade you want to finish with, or press one of the A, B, C, D buttons.
- Step 3Type what the final exam is worth — the syllabus usually says something like "final exam: 25 % of the course grade" — and read the score you need.
The arithmetic behind the answer
Your course grade at the end is a weighted average of two things: everything before the final, and the final itself. If the exam is worth w of the course, then the final grade is your current grade times (1 − w) plus your exam score times w. Turn that around to solve for the exam score and you get the number on this page: the grade you want, minus what you already have banked, divided by the weight of the exam.
One consequence surprises people every December: the smaller the final, the more extreme the answer. An exam worth 10 % of the class cannot move a grade far, so asking it to lift you two letters produces a number well above 100. An exam worth 40 % can move you a long way in either direction.
When the answer is above 100, or below zero
Above 100 means the grade you asked for is out of reach with this exam alone, and the page says so rather than printing a score you could aim at. What is still open is the best possible outcome, which is also shown: your current grade carried forward plus a perfect exam. Ask for that grade instead, or ask your instructor about extra credit or a replacement policy.
Below zero means the opposite and is worth knowing too: even a zero on the final leaves you at or above the grade you wanted. The page prints what a zero would actually leave you with, which is the honest way to say "you have already done it".
Two things the formula assumes
First, that your current grade really is the whole of the rest of the class. If some work is still ungraded, the figure will move again before the exam, and the answer moves with it.
Second, that the final is an ordinary weighted part of the grade. Some syllabi let the final replace your lowest test score, some make it mandatory to pass regardless of the average, and some are graded on a curve. Those rules sit outside the arithmetic — read the syllabus, then come back with the numbers it gives you.
Questions and answers
What grade do I need on the final?
Take the grade you want, subtract your current grade multiplied by everything the final is not worth, and divide by the weight of the final. With an 88 % now, a 90 % target and a final worth 30 %, you need 94.7 %.
What if my final is worth 20 %?
Then four fifths of your grade is already decided, and the exam can move your course grade by at most 20 points in either direction. Type 20 into the weight box to see exactly where that leaves you.
Can I still pass?
Look at the "a perfect final would give you" line under the answer. That is the highest your course grade can reach; if it is above the passing mark, it is still possible, and the score you need is the number above it.
My final replaces my lowest test. Does that change things?
Yes, and the page cannot know about it. Work out what your grade would be with that test replaced first — the grade calculator will do it — and use that number as your current grade here.