Grades and study · Exam scores and attendance
What score do you need on the final exam
Three numbers are enough: current average, target grade and the final’s weight. The tool also says whether the target is still in reach.
Calculate
How the calculator works
A US course grade is two pieces: the average you already have, which weighs (1 − w), and the final, which weighs w. The equation is solved for the only unknown — the exam score. If that number exceeds 100, even a perfect paper cannot get you there, and the page says so instead of printing an impossible figure.
Formula and method
needed = (target − current × (1 − w)) ÷ w
w is the final’s weight, written as a fraction.
ceiling = current × (1 − w) + 100 × w
The highest course grade you can still earn with a 100 on the final.
floor = current × (1 − w)
The course grade if you score zero on the final.
Most US college syllabi use this simple two-part weighting. The page does not model a drop-lowest-quiz rule, extra credit, a grading curve, or a policy that lets the final replace a midterm. Those rules are common and they change the number: read your syllabus before you relax or panic.
Worked example
78 now, aiming for 85, final worth 30%
current = 78, target = 85, weight = 30%.
- Already locked in: 78 × 0.7 = 54.6.
- Still needed: 85 − 54.6 = 30.4.
- 30.4 ÷ 0.3 = 101.3.
You would need 101.3: the B is out of reach. The best possible course grade is 84.6.
85 now, aiming for 88, final worth 30%
current = 85, target = 88, weight = 30%.
- Already locked in: 85 × 0.7 = 59.5.
- Still needed: 88 − 59.5 = 28.5.
- 28.5 ÷ 0.3 = 95.
95 on the final. Steep, but possible.
Input notes
- Current average
- The running average shown in the gradebook before the final, on a 0–100 scale.
- Target grade
- The overall course grade you want after the final is in.
- Final exam weight
- The percent of the course that the final is worth. It is on the syllabus, often 20–40%.
Assumptions and limits
Assumptions
- The current average already covers exactly (100 − weight)% of the course.
- No grade is dropped or replaced.
- The scale is linear, with no curve and no extra credit.
Limits
- No minimum exam score (some labs fail you below 60 on the final regardless).
- No end-of-term rounding (89.5 becoming an A−).
- No “the final replaces the lowest midterm” rule.
How to read the result
The most useful number is often the ceiling, not the score required. If the ceiling sits below your target, no amount of cramming will close the gap, and it is better to know that before finals week — so you can ask about extra credit or lower the target. A comfortable floor, by contrast, means you can aim higher without putting the credit at risk.
Common mistakes
Typing the weight as a fraction (0.3) instead of a percent (30).
The field expects a percent: 30, not 0.3.
Using the last quiz score as the current average.
Use the running course grade, covering everything already scored.
Ignoring a minimum score on the final.
Some US courses fail you on the final even if the average would pass.
Comparison
| Weight | To reach 80 | To reach 85 |
|---|---|---|
| 20% | 88 | 113 (impossible) |
| 30% | 84.7 | 101.3 (impossible) |
| 40% | 83 | 95.5 |
| 50% | 82 | 92 |
Related calculations
- Course grade by categoryOne line per category, with its score and its syllabus weight. The result is normalised, and the page tells you if weight is still missing.
- Grade as a percentPoints earned divided by points possible, times 100. The letter follows common US cutoffs, printed on the page so you can compare them with your syllabus.
- Attendance rateThe attendance percent, and the number that actually helps: how many meetings you can still miss before you fall under the cutoff.
- GPA calculatorEnter a letter and credits per course. The GPA is the sum of grade points times credits, divided by total credits.
Frequently asked questions
How do I know what I need on the final?
(target − current × (1 − weight)) ÷ weight.
Subtract the share already earned from the target, then divide by the final’s weight. With an 85 average, a target of 88 and a final at 30%, you need a 95.
What if the result is above 100?
The target is out of reach.
Even a perfect final would not be enough. The tool then shows the highest course grade you can still earn, so you can revise the target or look for points elsewhere.
What if I skip the final?
You land on the floor shown.
A zero on the final leaves course grade = current × (1 − weight). An 80 average with a 25% final becomes 60, aside from any excused-absence rule in the syllabus.
Author and update
Written by Rédaction HexaCalc (editorial team). Content last updated: August 25, 2026. No third-party medical or financial review is claimed.
- Les Éléments, Livre I (théorème de Pythagore) et Livre VII (algorithme d’Euclide) — Tradition mathématique euclidienne
Does the course use several grade categories?
The category-weighted grade calculator combines homework, midterms and the final.
Course grade by categoryCategory: Grades and study