What is a final grade calculator?
A final grade calculator tells you the score you need on your final exam to finish a class with the grade you want. You give it three numbers: your grade right now, how much the final counts, and the overall grade you're aiming for. It gives back one number, the score to beat.
This one does two more jobs on the same page, because the questions come in a set. Before you can ask "what do I need on the final?", you need to know your current grade, and that means a weighted average of everything so far. And once you have a number, you want to know if 87 is a B+. So the Final Grade Calculator has three tabs:
- Course Grade works out your weighted grade from each assignment, quiz and exam.
- Final Exam Needed works out the score you need on the final, plus a what-if grid.
- Letter Grade Scale shows which percentage maps to which letter and GPA value.
Every grade box takes a percentage (87) or a letter (B+). There's no account and nothing to install. The tab you're on is saved in the page address (#course, #final or #scale), so you can bookmark the one you use most.
How to calculate the grade you need on your final
The math is one line of algebra. Your overall grade is your current grade times the share of the course that's already done, plus your final exam score times the final's weight. Solve that for the final exam score and you get:
required score = (target − current × (1 − weight)) ÷ weight
Weight is the final's share of your grade as a decimal, so a final worth 30% is 0.30.
Worked example. You have an 82% going into the final. The final is worth 30%. You want an 88% overall, a B+.
required = (88 − 82 × 0.7) ÷ 0.3 = (88 − 57.4) ÷ 0.3 = 30.6 ÷ 0.3 = 102%.
The calculator shows "You need 102.0% on the final" and colors it gold: only possible with extra credit. The what-if grid shows a 90 on the final lands you at 84.4% (a B), and a perfect 100 gets you 87.4%.
That last line is the kind of thing the what-if grid catches. On this site's scale a B+ starts at 87, so 87.4% is a B+, even though it misses the 88% you typed as your target. The grid lights a cell green only when it reaches your target number, not your letter. If what you really want is the letter, type the bottom of that letter's range as your target (87 for a B+), not a number in the middle.
The result comes in four colors:
| Required score | What the calculator says |
|---|---|
| 0% or less | Green: you can skip the final and still hit your target. |
| Above 0% up to 100% | Green: the exact score you need, with its letter grade. |
| Above 100% up to 110% | Gold: only possible with extra credit on the exam. |
| Above 110% | Coral: not reachable through the final alone. |
Find your current grade first
The Final Exam Needed tab asks for your current grade. If your school's online gradebook shows one, use it. If it doesn't, or you don't trust it, the Course Grade tab works it out.
Here's the trick: enter only the work you've already finished, with the weights from your syllabus. Leave the final out, or add it as a row with the grade box empty: rows without a grade are skipped. The calculator divides by the total weight you entered, not by 100, so what you get back is your grade on the completed part of the course. That's exactly the "current grade" the final exam formula wants.
Say your syllabus looks like this, and the final hasn't happened yet:
| Component | Weight | Your score |
|---|---|---|
| Homework average | 20% | 92 |
| Quiz average | 10% | 85 |
| Midterm | 25% | 78 |
| Participation | 15% | 100 |
| Final exam | 30% | not taken yet |
Put the first four rows in Course Grade. Their weights add up to 70%, so the calculator shows a note that the weights don't total 100% and that the result is scaled to what you entered. That's what you want here. The answer is 87.7% · B+.
Now switch to Final Exam Needed. Current grade 87.7, final weight 30, target 85. You need 78.7% on the final to finish with an 85. Want a 90 instead? You'd need 95.3%. Happy with an 80? A 62.0% does it.
Once you get the final back, add it as a fifth row in Course Grade. The weights now total 100%, the note goes away, and you have your actual course grade.
What score do you need? A quick table
For a final worth 30% of the grade, here's the score needed for each common target. Anything over 100% needs extra credit.
| Current grade | To finish at 70% | To finish at 80% | To finish at 90% |
|---|---|---|---|
| 95% | 11.7% | 45.0% | 78.3% |
| 90% | 23.3% | 56.7% | 90.0% |
| 85% | 35.0% | 68.3% | 101.7% |
| 80% | 46.7% | 80.0% | 113.3% |
| 75% | 58.3% | 91.7% | 125.0% |
The weight of the final changes everything. With an 85% now and a 90% goal, here's what you'd need as the final gets heavier:
| Final is worth | Score needed for 90% | Score needed for 80% |
|---|---|---|
| 10% | 135.0% | 35.0% |
| 20% | 110.0% | 60.0% |
| 25% | 105.0% | 65.0% |
| 30% | 101.7% | 68.3% |
| 40% | 97.5% | 72.5% |
| 50% | 95.0% | 75.0% |
A light final protects the grade you have, for better or worse. A heavy one gives you room to climb, and room to fall. That's why the calculator asks for the weight instead of assuming one.
How much is one quiz or assignment worth?
Divide the category's weight by the number of items in it. If quizzes are 10% of your grade and there are 8 of them, each quiz is worth 1.25% of the course. Scoring 60 instead of 100 on one of them costs you 40 × 1.25% = 0.5 points on your overall grade. One bad quiz rarely sinks a class. One bad midterm worth 25% can move it by several points.
If your class uses points instead of percentages, turn the points into a percentage first. 45 out of 50 is 90%. To find a category's weight in a points system, divide its possible points by the course total: 200 homework points in a 1,000-point course is 20%. The percentage calculator does the division if you'd rather not.
For a single test, the test grade calculator turns "missed 7 out of 40" into a percentage and a letter.
The letter grade scale
The Letter Grade Scale tab uses a common US scale: A from 93, A- from 90, B+ from 87, B from 83, and so on down to D- at 60. Anything below 60 is an F. The GPA column runs from 4.3 for an A+ to 0.0 for an F. Plenty of schools cap an A+ at 4.0 instead, so check your registrar's policy before you use that number in the GPA calculator.
Your syllabus wins over any table. Some courses start an A at 94 or 95, or put the D/F line at 65. The percentages the calculator returns don't depend on the scale. Only the letter next to them does.
Letters as targets. When you type a letter, the calculator uses the middle of that letter's range: A- becomes 91, B becomes 84.5, F becomes 30. That's a fair stand-in for a grade you already got. As a target it aims higher than you need. With an 85% now and a 30% final, typing "A-" as your target asks for 105.0% on the final, while typing 90 asks for 101.7%. To aim for the bottom of a letter, type the number.
What this calculator doesn't do
It gives the straight weighted-average answer. It doesn't know your course's special rules, so adjust by hand for these:
- Dropped scores. If your lowest quiz is dropped, average only the quizzes that count and enter that.
- A final that replaces a midterm. Run it twice, once with each version of the midterm, and use the better result.
- Curves. They're applied at the end, at the instructor's discretion. The calculator shows the raw grade.
- A final split into parts. Treat the parts you've finished as completed work in Course Grade, and enter the remaining part's weight as the final.
- Cumulative GPA across several courses. That's what the GPA calculator is for.
Nothing you type is saved. The math runs in your browser, and closing the tab clears it. There's no sign-up and no trial, just the calculator.
Frequently asked questions
What do I need on my final to pass the class?
Set your target to your school's passing line, usually 60% (a D-) or 70% if your program requires a C-. With a 72% now and a 30% final, you need 32.0% on the final to finish at 60%, and 65.3% to finish at 70%.
How much will my grade drop if I fail the final?
Use the what-if grid. With an 85% now and a 30% final, scoring 50 on the final leaves you at 74.5%, a C. That's more than ten points gone. With a 10% final, the same 50 would leave you at 81.5%.
Can I enter grades as points, like 45/50?
Not as a fraction. Turn it into a percentage first: 45 ÷ 50 = 90%, then type 90. Weights work the same way. A category's weight is its possible points divided by the course's total points.
Can a grade go above 100%?
Yes, up to 110%. Each grade box accepts 0 to 110, so extra credit on an assignment counts. Anything above 110 is treated as a typo and ignored.
Why is my result different from my school's gradebook?
Usually because the gradebook includes something you left out: an ungraded category it counts as zero, a dropped score, or an assignment not entered yet. Line up each row with your syllabus weights and the two should agree.
Does it work for high school and college?
Yes. The math is the same wherever grades are weighted percentages. Only the letter scale changes between schools, and that only affects the letter shown next to your number.