Final Grade Calculator
This final exam calculator tells you the score you need on the final to finish the course with the grade you want. Enter your current grade, how much the final is worth and your target. With 84% now, a final worth 25% and a target of 90%, you would need 108%. You also get the score needed for 90, 80, 70 and 60, and the overall grade any final score would give you.
How to use the final exam calculator
- Enter your current grade as a percentage — the grade before the final. The default is 84.
- Enter the weight of the final exam, the share of the course grade it is worth. The default is 25%.
- Enter the grade you want overall. The default is 90.
- Read the required final score. With the defaults it is 108%, flagged as above 100%: not reachable without extra credit.
- Optionally, type a score in the if I score field to see what your overall grade would be.
Underneath, a table shows the final score needed for each of the four letter cutoffs. For the defaults:
| Target overall grade | Score needed on the final | What it means |
|---|---|---|
| 90% (A) | 108% | Not reachable without extra credit |
| 80% (B) | 68% | Reachable |
| 70% (C) | 28% | Reachable |
| 60% (D) | −12% | Already secured, even with a 0 |
A negative number is good news. It means the grade is locked in whatever happens on the exam. If you are not sure what your current grade is because your assignments carry different weights, work it out first with the weighted average calculator or the step-by-step guide to calculating your final grade.
The final grade formula
The formula comes from how the course grade is built. Your overall grade is a weighted average of two parts: everything before the final, worth 1 − w, and the final itself, worth w.
Set the overall grade to your target and solve for the final score. Subtract the part you have already earned, then divide by the weight:
With the defaults:
The 63 is worth seeing on its own. It is the number of course points you have banked: score 0 on the final and your grade is 63%. The final then contributes at most 25 more points, so the best possible grade is 63 + 25 = 88%. That is why 90% is out of reach.
Worked examples
Example: from a C+ to a B
Current grade 78%, final worth 20%, target 80%.
You need 88% on the final. Because the final is only worth 20%, raising the course grade by 2 points takes a final score 10 points above the current average.
Example: keeping an A
Current grade 91%, final worth 30%, target 90%.
You need about 87.67% on the final. You can score below 90 on the exam and still keep a 90 overall, because your current grade is above the target.
Example: the lowest score to pass with a C
Current grade 72%, final worth 40%, target 70%.
A 67% on the final keeps the C. With a heavily weighted final, though, a bad day moves the grade a long way: a 40% would drop the course grade to 43.2 + 16 = 59.2%.
What if I score…? Using the reverse calculation
The optional “if I score” field runs the formula forward. It takes your current grade and the weight, plugs in a final score and gives the overall grade. With the defaults:
| Final exam score | Overall grade |
|---|---|
| 100% | 88% |
| 90% | 85.5% |
| 85% | 84.25% |
| 80% | 83% |
| 70% | 80.5% |
| 60% | 78% |
| 0% | 63% |
Each 10 points on the final moves the course grade by 2.5 points, which is 10 × 0.25. This is a quick way to judge how much studying could change the outcome: on a 25% final, going from a 70 to an 80 on the exam lifts the course grade from 80.5% to 83%.
How the weight of the final changes everything
The same student, with an 85% current grade, needs very different final scores depending on how much the exam counts:
| Final worth | Needed for 90% | Needed for 80% |
|---|---|---|
| 10% | 135% | 35% |
| 20% | 110% | 60% |
| 25% | 105% | 65% |
| 30% | ≈ 101.67% | ≈ 68.33% |
| 40% | 97.5% | 72.5% |
| 50% | 95% | 75% |
A light final protects the grade you have: you cannot fall far, but you cannot climb far either. A heavy final cuts both ways. If you are trying to move up a letter, a final worth 40% or more gives you room to do it; if you are trying to hold on, it is a risk.
When the course uses points instead of percentages
If the syllabus gives totals in points, work in points. Say the course has 1,000 points, the final is worth 200, and you have 650 of the 800 points available so far (81.25%). An A needs 900 points, which would take 250 on a 200-point final, so it is out of reach. A B needs 800 points, so you need 150 of 200 — 75% on the final. Entering 81.25 as the current grade with a 20% weight gives the same answers, since 200 is 20% of 1,000.
When more than the final is left
The calculator assumes the final is the only thing left. If a project or another test is still to come, you need one extra step.
Say your current grade of 84% covers 60% of the course, a project worth 15% is still due, and the final is worth 25%. You want 85% overall.
If you expect 95% on the project, you need 81.4% on the final. If you would rather not guess the project score, treat the project and the final as one block worth 40%: (85 − 50.4) ÷ 0.4 = 86.5, so you need to average 86.5% across the two, weighted by their shares.
Weights are often given in the syllabus as fractions or decimals rather than percentages. The decimal to percent calculator converts a weight like 0.15 or 3/20 so you can enter it here, and the percentage calculator finds what share of the total points a component is worth.
Common mistakes
- Using an unweighted current grade. If homework and tests count differently, a plain average of all your scores is not your current grade. Use the course’s weights, or the average calculator only when every item counts the same.
- Entering the weight as a whole number in a hand calculation. 25% is 0.25 in the formula. Dividing by 25 instead gives a required score of 1.08 and nonsense.
- Forgetting that other work is still to come. If there are assignments left besides the final, your “current grade” and weight do not cover the whole course. Treat the remaining work and the final together as one combined weight, or recalculate once those grades are in.
- Assuming a 90% exam average gives a 90% course grade. Only if every component is also at 90%.
- Ignoring rounding rules. Whether 89.5% counts as an A is up to the school. The rounding calculator shows what a score becomes under different rules, but the syllabus decides which applies.
- Reading a negative answer as an error. It means the target is already guaranteed.
For a single test score as a percentage and letter, use the grade calculator. To turn a raw score such as 43 out of 50 into a percentage first, see X out of Y as a percentage.
Frequently asked questions
What do I need on my final to get an A?
Use (90 − current × (1 − w)) ÷ w, where w is the final’s weight as a decimal. With an 85% current grade and a final worth 40%, you need (90 − 51) ÷ 0.4 = 97.5%. If the answer is above 100, an A is not reachable without extra credit; letter cutoffs vary by school.
How do you calculate what you need on a final exam?
Multiply your current grade by the share of the course already done, subtract that from your target, and divide by the final’s weight. For 78% now, a 20% final and a target of 80%: 78 × 0.8 = 62.4, 80 − 62.4 = 17.6, 17.6 ÷ 0.2 = 88%.
What happens to my grade if I get a 0 on the final?
Your grade becomes your current grade times 1 − w. With 84% and a final worth 25%, a zero leaves you at 84 × 0.75 = 63%. That is the floor your grade cannot drop below, and the calculator’s table shows a negative required score for any target at or below it.
How much will my final exam affect my grade?
Each point on the final moves your course grade by the final’s weight. On a final worth 25%, every 10 points on the exam shifts your overall grade by 2.5 points. The maximum change, from scoring 0 to scoring 100, equals the weight itself, so a 25% final can move you at most 25 points.
Why does the calculator say I need more than 100%?
Because even a perfect final would not lift your grade to the target. With 84% now and a 25% final, a 100% final gives 63 + 25 = 88%, so a 90% would need a 108% score. Only extra credit or a curve could close the gap. Try a lower target to see what is reachable.
What is a final exam calculator?
A final exam calculator works out the score you need on a final exam to reach a chosen course grade, given your current grade and how much the final is worth. It rearranges the weighted average formula, overall = current × (1 − w) + final × w, to solve for the final score.
What if my final is worth 50% of my grade?
Then the final counts as much as everything else combined. With an 85% current grade, you need 95% on the final for a 90% overall and 75% for an 80%. Every 10 points on the exam moves your course grade by 5 points, so the final has more power to raise or drop your letter than your current grade does.
Related calculators
Guides that use this calculator
Longer explanations of the method behind it, with worked examples.
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