Final Grade Calculator: What Do I Need on My Final?
Enter your current grade and what the final is worth. We show the score you need for every letter grade at once — plus the best grade you can still finish with.
To finish with a B you need
to finish this course with a B (80%)
Best you can finish with87.2%
If you score zero67.2%
Top grade reachableA−
What you need for every grade
Final course grade
Needed on the final
A · 90% or better
Not reachable
A− · 87% or better
99%
B+ · 83% or better
79%
B · 80% or better
64%
B− · 77% or better
49%
C+ · 73% or better
29%
C · 70% or better
14%
D · 60% or better
Already there
Pass · 60% or better
Already there
Worked from a current grade of 84% and a final worth 20%.
“Already there” means even a zero on the final leaves you above that line.
This calculator needs JavaScript to recalculate. The answer shown above was worked out when the page was built and is correct for the date in the address bar.
Your grade going into the final is already fixed. The final is worth a fixed slice of the course. The only thing still moving is the score you get on the final — so the question has exactly one unknown in it, and it has an exact answer.
Split the course in two. The locked portion is everything already graded. The live portion is the final. If the final is worth 20%, then 80% of your course grade is already decided and cannot change, and the final can move your overall grade by at most 20 points in either direction. That single fact answers most of the panic: a final worth 15% cannot rescue a 58%, and a final worth 40% will not let a 94% coast.
Additive finals and replacement finals
Read your syllabus carefully here, because the two cases give different answers. An additive final has its own weight alongside homework, quizzes and midterms — that is what this calculator assumes. A replacement final drops into an existing category, usually replacing your lowest test score. If yours replaces something, your current grade will change when the final is entered, and this calculation will read low. Work the replacement out on the weighted grade calculator first, then come back.
Worked example
Current grade 84%. The final is worth 20%. You want a B, which your syllabus puts at 80%.
Still needed: 80 − 67.2 = 12.8 points, out of the 20 the final is worth.
Required score: 12.8 ÷ 0.20 = 64%.
Your ceiling: 67.2 + 20 = 87.2% — the best this course can still finish at, even with a perfect final.
Your floor: 67.2% — what you finish with if you score zero.
When the answer is impossible
Current grade 61%, final worth 15%, and you want an 80%. The formula returns 191.7%. That is not a score, it is a message: an 80% is gone. Your ceiling from here is 66.85%, so the honest answer is that a D is secure, a C− is out of reach, and the useful decision now is about the rest of your schedule rather than this final.
Most calculators print 191.7 and leave you to work that out. This one says it.
The formula
With w as the final's weight written as a decimal (20% → 0.20):
required = (target − current × (1 − w)) ÷ w
ceiling = current × (1 − w) + 100w
floor = current × (1 − w)
Three assumptions are baked in, and all three are worth checking against your syllabus: your current grade is already correctly weighted across its categories; the final is additive rather than replacing a category; and there is no extra credit. Extra credit in particular breaks the ceiling, because the maximum stops being 100.
Where this stops being reliable
We compute what the syllabus says. We cannot know what your instructor will do at the margin, and at the margin is where a lot of grades are decided. Rounding conventions vary — some instructors take 89.5% to an A−, some do not, and almost none write it down. Pass/fail courses have a threshold set by your institution, not by the usual 60%. Sections of the same course sometimes weight the final differently. And if your syllabus drops your lowest test and the final counts as a test, this arithmetic is simply the wrong model for your course. When the number lands within a point of a boundary, the number is not the answer — asking your instructor is.
Common questions
What do I need on my final to get an A?
Take the A threshold from your syllabus (usually 90%), subtract your current grade multiplied by everything the final is not worth, then divide by the final's weight. With an 84% and a final worth 20%: (90 − 84 × 0.80) ÷ 0.20 = 114% — not reachable. The calculator above shows every letter grade at once so you can see immediately which ones are still live.
What if the calculator says I need more than 100%?
Then that grade is mathematically out of reach without extra credit, and no amount of studying changes it. Look at the ceiling figure instead — that is the best grade you can still finish with if you get a perfect score on the final. It is a more useful number than a required score you cannot achieve.
My final replaces my lowest test grade. How do I work that out?
Differently, unfortunately. A replacement final changes your current grade rather than adding to it, so this calculator will read low. Work out your grade in the weighted grade calculator twice — once with your lowest test as it stands, once with a candidate final score in its place — and compare. Some syllabi replace only if the final is higher, which means the replacement can never hurt you.
Does my current grade already include the final?
It should not. If your gradebook shows a final exam entry with a zero or a blank in it, your displayed grade is probably already counting the final as unearned, which makes it read far lower than your true standing. Use the grade with the final excluded. Most systems have a setting for exactly this, usually called something like "treat ungraded as zero".
What is the lowest grade I can still finish the course with?
That is your floor: your current grade multiplied by everything the final is not worth. With an 84% and a 20% final, the floor is 67.2% — so even a zero on the final leaves you with a D+. The calculator shows this alongside the ceiling.
My syllabus says the final is 20% of the course. Is that the same as 20 points?
Yes, in the sense that matters here. A final worth 20% can shift your overall course grade by up to 20 percentage points — down to your floor or up to your ceiling. That is the whole range, and it is a useful sanity check on any answer you get.
Can I pass if I fail the final?
Often, yes. If your floor is above your institution's pass mark, you pass regardless of what happens on the final. Enter your numbers above and check the floor figure — it is the one question this page can answer with complete certainty.