The Quick Answer
To find the score you need on your final exam:
Required Final Score = (Target Grade × 100 − Current Grade × (100 − Final Weight)) ÷ Final Weight
For example, if your current grade is 82%, your target is 90%, and the final is worth 40%:
Required = (90 × 100 − 82 × 60) ÷ 40 = (9000 − 4920) ÷ 40 = 102.00%
That means a 90% is not reachable — you'd need more than a perfect score. Use the Final Grade Calculator to run your own numbers instantly.
Why This Formula Works
Your course grade is a weighted average of two components: the work you've already done and the final exam.
Course Grade = (Current Grade × Coursework Weight) + (Final Score × Final Weight)
Both weights are expressed as decimals that add up to 1.0. If the final is worth 30%, then coursework is worth 70% (0.70).
The formula above simply solves this equation for the unknown — your final exam score — given a target course grade.
Breaking Down the Variables
- Current Grade — your grade on all coursework excluding the final. Find this in your LMS (Canvas, Blackboard, Moodle) or calculate it with a Grade Calculator.
- Target Grade — the overall course grade you want. Common targets: 90% (A), 80% (B), 70% (C).
- Final Weight — the percentage of your total course grade determined by the final exam. Check your syllabus.
Worked Examples
Example 1: Comfortable cushion
You have a 91% in Chemistry. The final is worth 25%. You want to keep an A (90%).
Required = (90 × 100 − 91 × 75) ÷ 25 = (9000 − 6825) ÷ 25 = 87.00%
You can score below your current average and still get an A. Low pressure.
Example 2: Tight but possible
You have a 78% in History. The final is worth 35%. You want a B (80%).
Required = (80 × 100 − 78 × 65) ÷ 35 = (8000 − 5070) ÷ 35 = 83.71%
An 84% on the final gets you there. Focused study on the material most likely to appear on the exam can make this achievable.
Example 3: Mathematically impossible
You have a 72% in Statistics. The final is worth 20%. You want a B (80%).
Required = (80 × 100 − 72 × 80) ÷ 20 = (8000 − 5760) ÷ 20 = 112.00%
You'd need 112%, which isn't possible without extra credit. Your realistic ceiling is:
Max Course Grade = 72 × 0.80 + 100 × 0.20 = 57.6 + 20 = 77.6%
Example 4: Already safe
You have a 96% in English. The final is worth 30%. You want at least a 90% (A).
Required = (90 × 100 − 96 × 70) ÷ 30 = (9000 − 6720) ÷ 30 = 76.00%
Even a C-level performance on the final keeps your A intact.
What Affects the Required Score Most?
Three factors control how hard your final has to work:
1. Final exam weight
The heavier the final, the more influence it has — in both directions.
| Final Weight | Current: 80%, Target: 85% | Required Score |
|---|---|---|
| 15% | 80 → 85 | 113.33% (impossible) |
| 25% | 80 → 85 | 100.00% (barely possible) |
| 35% | 80 → 85 | 94.29% (difficult) |
| 50% | 80 → 85 | 90.00% (doable) |
A heavier final gives you more room to recover from a low coursework grade — but also more risk if you perform poorly.
2. Gap between current and target
Small gaps are easy to close. Large gaps require exceptional performance or are simply impossible.
- Gap of 0: You need the same score as your current grade (steady state).
- Gap of 5: Usually recoverable if the final has meaningful weight (25%+).
- Gap of 10+: Often requires near-perfect performance unless the final is heavily weighted.
3. Your current grade
If your current grade is already above your target, the required final score drops below your target. This is the "cushion effect" — strong coursework performance reduces pressure on the final.
Common Mistakes
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Using the wrong current grade. Your current grade should exclude the final. If your LMS includes a placeholder 0% for the final, your displayed grade is artificially low. Recalculate without the final, or use the "current grade excluding unsubmitted" view.
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Confusing points with percentages. If the final is worth 200 out of 500 total points, the weight is 200 ÷ 500 = 40%, not 200%.
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Forgetting about other pending work. If you still have assignments due before the final, your "current grade" will change. Run the calculator again after submitting everything else.
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Ignoring the maximum possible grade. Before stressing about a target, calculate the best grade you can get (assume 100% on the final). If that's below your target, adjust your goal.
Strategies When the Numbers Look Bad
If the required score is uncomfortably high:
- Run multiple targets. What do you need for an A vs. a B? Sometimes dropping one letter grade cuts the required score by 20+ points.
- Check for extra credit. Some courses offer bonus points that can push your effective maximum above 100%.
- Prioritize across courses. If you're juggling multiple finals, calculate required scores for all of them and allocate study time where the marginal return is highest.
- Talk to your instructor. If you're close to a grade boundary, some professors consider effort, participation, or improvement trends.
How to Find Your Final Exam Weight
Your syllabus lists the grading breakdown. Look for something like:
- Assignments: 30%
- Midterm: 20%
- Participation: 10%
- Final Exam: 40%
If the syllabus uses points instead of percentages, divide the final's points by total possible points:
Weight = Final Points ÷ Total Course Points × 100
Example: Final is 150 points out of 600 total → Weight = 150 ÷ 600 = 25%
Frequently Asked Questions
Does this formula work for pass/fail classes?
Only if you know the numeric cutoff. If "pass" requires 60%, set 60 as your target grade and use the formula normally.
Can I use this for midterms?
Yes. Replace "final weight" with the midterm's weight and "current grade" with your grade on everything before the midterm. The math is identical.
What if my course has multiple remaining exams?
This formula handles one unknown at a time. If you have two exams left, you'd need to estimate one score to solve for the other — or treat both as a combined block with a combined weight.
My current grade is 0% because nothing is graded yet. What do I do?
If no coursework is graded, the formula breaks down (there's no meaningful "current grade" to work with). Wait until you have at least a few graded assignments, then run the calculator.
Does rounding matter?
Slightly. If the calculator says you need 89.50% and your professor rounds to whole numbers, you need a 90%. Always round up when the required score falls on a boundary.
Calculate Your Required Score
Use the Final Grade Calculator to plug in your own numbers. You can also figure out your current weighted grade with the Grade Calculator, or convert your final grade to GPA using the Percentage to GPA Converter.