About Final Grade Calculator
The score you need on a final exam is (target grade - current grade x (1 - final weight)) / final weight. With an 85% current grade, a final worth 25% and a target of 80%, that is (80 - 63.75) / 0.25 = 65%. This page does that sum and then answers the follow-up questions: a table of the exam score needed for each letter grade from A down to D-, a second table of the course grade you would finish with for final scores from 100% to 0%, and the course grade for one score you choose. It also tells you when a target is out of reach or already secured.
Formula for the grade needed on a final exam
Needed final score = (target grade - current grade x (1 - w)) / w, where w is the final exam weight as a decimal
Your current grade covers the share of the course that is not the final, which is 1 - w. Multiplying the two gives the course points you have already earned. Subtract them from the target to find the points the exam still has to supply, and divide by w to turn that into an exam percentage. Example: current 88%, final worth 20%, target 90%. Points earned: 88 x 0.8 = 70.4. Points still required: 90 - 70.4 = 19.6. Exam score: 19.6 / 0.2 = 98%. Running it the other way, course grade = current x (1 - w) + final score x w, so a 95% exam there gives 70.4 + 19 = 89.4%, just short.
Score needed on the final for an A- (90%) by current grade and exam weight
Each cell is the exam score required to finish the course at 90%. Figures above 100% mean a 90% finish is not possible without extra credit.
| Final exam weight | Current 80% | Current 85% | Current 90% | Current 95% |
|---|---|---|---|---|
| 10% | 180% | 135% | 90% | 45% |
| 15% | 146.67% | 118.33% | 90% | 61.67% |
| 20% | 130% | 110% | 90% | 70% |
| 25% | 120% | 105% | 90% | 75% |
| 30% | 113.33% | 101.67% | 90% | 78.33% |
| 40% | 105% | 97.5% | 90% | 82.5% |
| 50% | 100% | 95% | 90% | 85% |
When your current grade equals the target, you need exactly the target on the exam whatever its weight.
Score needed on the final for a B- (80%)
The same grid for an 80% finish. Negative figures mean the grade is already secured even with a zero on the exam.
| Final exam weight | Current 70% | Current 75% | Current 85% | Current 90% |
|---|---|---|---|---|
| 10% | 170% | 125% | 35% | -10% |
| 15% | 136.67% | 108.33% | 51.67% | 23.33% |
| 20% | 120% | 100% | 60% | 40% |
| 25% | 110% | 95% | 65% | 50% |
| 30% | 103.33% | 91.67% | 68.33% | 56.67% |
| 40% | 95% | 87.5% | 72.5% | 65% |
| 50% | 90% | 85% | 75% | 70% |
Worked examples
Inputs are listed as current grade, final exam weight, target course grade, and the optional expected score.
Holding on to a B-
Current 85%, weight 25%, target 80%, expected score 75%
Needed on the final: 65%. With 75% on the final the course grade is 82.5% (B-).
The letter-grade table for these inputs shows 77% for a B, 93% for a B+ and marks A- and A as not reachable.
Chasing an A- with a small final
Current 88%, weight 20%, target 90%, expected score 95%
Needed on the final: 98%. With 95% the course grade is 89.4% (B+).
A heavy final and a borderline pass
Current 72.5%, weight 40%, target 70%, expected score 66.3%
Needed on the final: 66.25%. With 66.3% the course grade is 70.02% (C-).
A target that is out of reach
Current 89.5%, weight 30%, target 93%, expected score 100%
Needed on the final: 101.17%. A perfect exam gives 92.65% (A-).
The page shows a warning with the highest course grade a perfect final can produce.
A grade that is already safe
Current 95%, weight 10%, target 80%, expected score 0%
Needed on the final: -55%. With 0% the course grade is still 85.5% (B).
Letter grade scale used for the tables
Letter grades on this page follow a common US plus/minus scale. It is an assumption, not a rule: many schools use 90/80/70/60 without plus and minus, and some instructors round up. Type your own cut-off as the target if it differs.
| Letter grade | Minimum course percentage |
|---|---|
| A | 93% |
| A- | 90% |
| B+ | 87% |
| B | 83% |
| B- | 80% |
| C+ | 77% |
| C | 73% |
| C- | 70% |
| D+ | 67% |
| D | 63% |
| D- | 60% |
| F | Below 60% |
No rounding up is applied: 89.4% is shown as a B+, not an A-.
What this calculator assumes and what it cannot do
- Your current grade must already be the weighted grade for everything except the final. If you only have separate assignment scores, combine them first with the weighted grade calculator.
- The final is treated as one item with one weight. Courses that drop the lowest exam, replace a midterm with the final, or require a minimum exam score to pass are not modeled.
- Grades are percentages. Convert points first: 132 out of 150 is 88%.
- Results are rounded to two decimals. If you need 84.67%, aim for at least 85% to be safe.
- Current and target grades may go above 100 to allow for extra credit, up to 200. The weight must be above 0 and at most 100.
- Curves and instructor rounding are not included. Your syllabus and instructor have the final say.
Step by step
- 1
Enter your Current grade as a percentage. This is your grade on everything except the final.
- 2
Enter the Final exam weight, the percentage of the course grade the final is worth (25 for 25%).
- 3
Enter your Target course grade, such as 90 for an A- or 70 for a C-.
- 4
Optionally fill in Score you expect on the final to see the course grade and letter grade that score would give. Leave it blank to skip this.
- 5
Read Needed on the final, then check the two tables for every letter grade and every final score.