Semester Grade Calculator
Your quarter grades and the weighting your school uses. You get the semester grade you're carrying, the range the final exam can still put you in, and the exact score each letter would take.
The weighting is yours to edit — how much the exam counts is a school decision, and schools disagree about it.
Your semester
Pick the weighting your school uses, then type in the grades you already have. Leave the exam blank until you sit it — that's the piece this page solves for.
The most common US high-school semester. Niskayuna CSD writes it as doubling each quarter and averaging in the exam, which is the same arithmetic.
| Counts as | Weight | Your grade |
|---|---|---|
| Quarter 1 | ||
| Quarter 2 | ||
| Final exam |
Where you stand
You're averaging 85.0% on the 80% of the semester that's already graded, which is a B. The 20% still ahead of you can land the semester anywhere between 68.0% and 88.0% — a swing of 20 points.
The final exam has to score 95.0%.
What each letter costs
The same question asked for every letter at once. These cut-offs are two common conventions, not a standard — yours are printed on your syllabus, and the test grade calculator lets you type your own in.
| Letter | Semester needs | You'd need |
|---|---|---|
| A | 90% | 110.0% — out of reach |
| B | 80% | 60.0% |
| C | 70% | 10.0% |
| D | 60% | already yours |
Nothing is capped. A figure above 100% is a letter the exam can no longer reach on its own, and one at or below zero is a letter you hold whatever happens — both are more useful said plainly than rounded into the range.
Informational only — this is not your official grade. It's what your numbers produce under the weighting you gave it, and the weighting is set by your school, not by this page. Exam exemptions, curves, rounding rules and grade replacement policies are your teacher's and your school's, and they record the real grade. Nothing you type here leaves your browser.
How this is calculated
A semester grade is a weighted average, and every figure on this page comes out of one. Each piece of the semester earns points equal to its grade times its weight; the pieces you've finished are added up, and what's left is solved for.
Points banked= Σ (grade × weight ÷ 100), graded pieces only
Grade so far= points banked ÷ graded weight × 100
Exam score a target needs= (target − points banked) ÷ remaining weight × 100
Best and worst still possible= points banked + remaining weight × (100 or 0) ÷ 100
Worked through with the example the page loads with: an 88 in Quarter 1 and an 82 in Quarter 2, on the 40/40/20 weighting. Quarter 1 earns 88 × 40 ÷ 100 = 35.2 points and Quarter 2 earns 32.8, so 68 points of the semester's 100 are banked and the average across the 80% graded is 85%. The exam holds the other 20 points, which puts the finish line somewhere between 68% and 88% — a 20-point swing. A B+ at 87% needs (87 − 68) ÷ 20 × 100 = 95% on the exam. An A at 90% needs 110%, so on these numbers the A is gone, and the page says so rather than printing an impossible target as if it were a plan.
Where the weightings come from
The four presets are published policies, not a standard, and they disagree — which is the whole reason the weights are inputs. If your handbook says something else, type that in; the arithmetic doesn't care, and only your school's numbers produce your school's grade.
What it assumes
- Each quarter grade is already a percentage. If yours arrives as a letter, this page can't un-convert it — a B could be anything from 83 to 86, and guessing would change the answer. Use the percentage your gradebook shows.
- Weights are used exactly as you enter them. They are not rescaled to 100. If they don't total 100 the page says so and reports points on your own scale, because a scheme that doesn't add up is a handbook to re-read.
- A blank is ungraded, not a zero. Leaving the exam blank is what makes it the thing being solved for. Enter a 0 only if you actually scored one.
- Nothing is capped. A required exam score above 100% means the letter is out of reach; at or below zero it means you already hold it. Both are printed as they come out.
Where this stops being right
- Exam exemptions and replacement rules. Many schools let a strong average exempt you from the exam, or replace a weak quarter with the exam score. Those are policies, not arithmetic. If you're exempt, use the two-quarter weighting; if a quarter gets replaced, enter the grade that will actually stand.
- Rounding. Whether an 89.5 becomes a 90 is your school's rule and isn't applied here. Figures are shown to one decimal place, unrounded.
- Inside a quarter, this is the wrong tool. It works from finished quarter grades. If the quarter itself is still running and you want it built up from homework, quizzes and tests, the weighted grade calculator does that, and the final grade calculator solves the same “what do I need” question one course at a time.
- A semester grade is not a GPA. What the letter is worth in grade points is a separate institutional decision — the high school GPA calculator handles that, including honors and AP weighting.
- This is not your official grade. Your teacher records it and your school keeps it. If either disagrees with this page, they are right.
Sources
Multiplying by a weight needs no authority. The claim that does need one is that the weighting is local and genuinely varies — so here are three published positions that disagree with one another.
Niskayuna Central School District, High School Grading Policy: for a semester course, final grades are calculated by “doubling the value of the grades for each quarter” and including the final exam — five equal parts, which is the 40/40/20 weighting written a different way.
Broward County Public Schools, High School Grading & Grade Point Averages: “each quarter grade equals 37.5 percent of the final semester grade” and “the final exam grade equals 25 percent” — the same two quarters and one exam, weighted differently enough to move letters.
Howard County Public School System, Policy 8020 Implementation Procedures — Grading and Reporting: sets the final exam at 20% of the final grade for state-assessed courses, and publishes no single formula covering every other course — evidence that even within one district the weighting can be a course-level fact rather than a system-wide one.
Those three are cited as verifiable examples, not as rules governing your course. What they establish together is the point this tool is built on: there is no universal answer to “how much does the final count”, so the honest calculator asks you.
Last reviewed: August 2026
Frequently asked questions
How is a semester grade calculated?
Each piece is multiplied by the share your school gives it, and the results are added. Under the most common US high-school weighting — each quarter 40%, the final exam 20% — an 88 and an 82 come to 35.2 + 32.8 = 68 points of the 80 already graded, an 85% average, and the exam supplies the last 20 points. What you can't take from a calculator is the weighting itself: it is set by your school or district and it genuinely differs, so read it off your handbook or syllabus and type it in.
What do I need on the final exam to get a B for the semester?
Subtract the points you've already banked from the points the letter needs, then divide by the weight of the exam. With 68 points banked and the exam worth 20%, a B at 83% needs (83 − 68) ÷ 20 × 100 = 75% on the exam. The table on this page runs that for every letter at once, and says plainly when a letter is out of reach — a figure above 100% means no exam score can get you there.
Is the final exam always 20% of the semester grade?
No. 40/40/20 is the most common arrangement, but Broward County Public Schools weights each quarter at 37.5% and the exam at 25%, and Howard County publishes a 20% exam only for state-assessed courses, leaving other courses to local decisions. Some schools exempt students from the exam entirely, which makes the two quarters the whole grade. The weights on this page are editable for that reason.
Can my final exam still change my grade?
That is the number this page leads with. Score the exam at 100 and at 0 and you get the two ends of what's still possible: with an 85% average across two quarters and a 20% exam, the semester finishes somewhere between 68% and 88%. Anything outside that range is already decided, whatever the exam does — which is worth knowing before you decide how much of the weekend it gets.
Related tools
Enter your syllabus weights and the scores you've had back. See your grade right now and the exact score the work that's left has to average.
Open tool →Weighted Grade CalculatorYour course grade weighted the way the syllabus weights it, with each component's contribution itemized. Takes marks as percentages or as they were handed back — 17/20.
Open tool →Test Grade CalculatorHow many questions the test had and how many you got wrong. See the percentage, the letter it earns on your course's own cut-offs, and how many questions each letter costs.
Open tool →High School GPA CalculatorYour courses, your grades, and which ones were honors or AP. See both GPAs at once — unweighted out of 4.0, and weighted on your own district's bonus rule rather than a guessed one.
Open tool →