InfiniteCalc

Grade Calculator

Find your weighted course grade and the score you need on the final exam.

One item per line: Name, Score %, Weight % — e.g. "Homework, 92, 30".

%

Optional — the overall course grade you want

%

Optional — how much the final exam counts toward the course grade

A grade calculator turns a stack of assignment scores and syllabus weights into one clear number: your current grade in the course. Enter each category with its score and weight — homework, quizzes, midterms — and the calculator computes your weighted average exactly the way your instructor does.

It also answers the question every student asks near the end of the semester: "What do I need on the final?" Enter your desired course grade and the final exam’s weight, and you will see the minimum final exam score required — whether that is a comfortable 62% or an impossible 112%.

How Weighted Grades Work

A weighted grade multiplies each score by its category weight, sums the products, and divides by the total weight used:

Grade = Σ(score × weight) ÷ Σ(weight)

For example, Homework 92% at 30% weight, Quizzes 85% at 20%, and a Midterm 78% at 25% gives (92×30 + 85×20 + 78×25) ÷ 75 = (2,760 + 1,700 + 1,950) ÷ 75 = 85.5%.

Dividing by the weight used so far (75%, not 100%) is the key step — it shows your standing on completed work only. If your syllabus grades on points instead of percentages, use each category’s points-earned percentage as the score and its share of total points as the weight.

The "What Do I Need on the Final?" Formula

When only the final exam remains, your course grade is a blend of your current grade and your final exam score:

Needed Final Score = (Desired Grade − Current Grade × (1 − w)) ÷ w

where w is the final exam weight as a decimal (25% = 0.25).

Reading the result: - Under 0%: you have already locked in your desired grade - 0%–70%: very achievable with normal preparation - 70%–90%: doable, but budget serious study time - 90%–100%: possible only with a near-perfect exam - Over 100%: mathematically out of reach — ask about extra credit, or adjust your target to what is attainable

Example: Aiming for an A− (90%)

A student has Homework 92% (30% weight), Quizzes 85% (20%), and a Midterm 78% (25%), with a final exam worth the remaining 25%.

Current weighted grade = (92×30 + 85×20 + 78×25) ÷ 75 = 85.5%.

Needed on the final for a 90% overall: (90 − 85.5 × 0.75) ÷ 0.25 = (90 − 64.1) ÷ 0.25 = 103.5% — not possible without extra credit.

For an 87% overall instead: (87 − 64.1) ÷ 0.25 = 91.5% — hard but achievable. And to simply hold 85%? Just (85 − 64.1) ÷ 0.25 = 83.5%. Running these scenarios before finals week tells you exactly where to spend your study hours.

Frequently Asked Questions

How do I calculate my grade with weighted categories?

Multiply each category score by its weight, add the results, and divide by the sum of the weights. For example, 90% homework at 40% weight plus 80% exams at 60% weight gives (90×40 + 80×60) ÷ 100 = 84%. If some categories are not graded yet, divide by only the weights completed so far.

What grade do I need on my final to pass?

Use the formula: (Desired − Current × (1 − w)) ÷ w, where w is the final’s weight as a decimal. If you have an 82% and need 70% to pass with a final worth 20%, you need (70 − 82 × 0.8) ÷ 0.2 = 22% — meaning even a rough exam day still passes the course.

What if my weights do not add up to 100%?

While the course is in progress, that is normal — ungraded work has not been counted yet. The calculator divides by the weight used so far, giving your grade on completed work. If your syllabus weights genuinely exceed 100%, something is misentered; recheck the syllabus percentages.

What letter grade is a 85 percent?

On the most common US scale, 85% is a B. Typical cutoffs are: A 93+, A- 90–92, B+ 87–89, B 83–86, B- 80–82, C+ 77–79, C 73–76, C- 70–72, D 60–69, F below 60. Cutoffs vary by school and instructor, so always confirm with your syllabus.

Can my final exam replace a lower midterm grade?

Only if your instructor has a replacement policy — some syllabi let a higher final score replace the lowest exam grade. This calculator assumes standard weighting with no replacement. If your course has such a policy, run two scenarios: one with the original midterm and one with it replaced by your projected final score.

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