Final grade calculator
Find the score you need on the final exam to finish the course with the grade you want.
The numbers in the fields are examples. Letter labels in the table use a common 90/80/70/60 scale; your school's may differ.
What the number means
A course grade is a weighted average: every graded part counts in proportion to its weight. Before the final, part of that average is already fixed. The final exam fills in the rest, so asking "what do I need on the final?" is the same as solving the weighted-average equation for one unknown. The answer is a percentage of the final exam's own scale, not a share of the whole course.
The formula
Needed on the final = (goal − current grade × (1 − w)) ÷ w, where the current grade is your weighted result for everything graded so far, w is the final's weight written as a fraction (30% is 0.30), and the goal is the course grade you want. It comes from rearranging course grade = current × (1 − w) + final × w. In points mode the same idea is simpler: needed points = goal × total points − points earned, and the share of the final is needed points ÷ the final's points.
Worked example
A student has 86% before the final. The final is worth 30%, and the goal is an A at 90%. The graded part contributes 86 × 0.70 = 60.2 course points. The goal is 90, so the final has to add 29.8 points. Since the final carries at most 30 points of the course, the student needs 29.8 ÷ 0.30 = 99.33% on the exam. For a B at 80% the figure drops to 66%. Scoring zero on the final would leave the course at 60.2%, which shows how much room the final has: its weight times the gap between the best and worst case, here 30 percentage points.
Common mistakes
The first mistake is mixing up two different "current grades". A running total shown by a learning platform may count only graded work (correct input here) or may count ungraded items as zero (not correct). The second is using the final's weight as a share of what is left. If the final is 30% of the whole course, type 30, not the share of the remaining work. The third is forgetting the syllabus rules that sit outside the weights: a minimum score on the final to pass, a rule that the final replaces the lowest test score, or a cap on extra credit. The calculator treats the weights as the only rule.
Limits of this method
If your instructor drops the lowest quiz or the final replaces a weaker exam, the weights you type here are no longer the weights that decide the grade; recompute the "current grade" after the drop. Grading scales also differ: 90/80/70/60 is a common set of cutoffs for A to D, but plus and minus grades, curved courses and pass-fail courses use other thresholds, so use the "Course grade I want" field with the number your syllabus gives. Finally, a percentage needed above 100 is not a prediction, only a statement that the goal is out of reach by this exam alone.
What do I need on my final exam to get the grade I want?
Take the grade you have before the final, the share of the course the final is worth, and your goal. The score you need is (goal − current grade × (1 − final weight)) ÷ final weight. With 86% before the final, a final worth 30% and a goal of 90%, the part of the course already graded contributes 86 × 0.70 = 60.2 points toward the 90, so the final must supply the other 29.8 points out of its 30 — a score of 99.33%. For a goal of 80% the same student needs only 66%.
What if the number comes out above 100%?
Then the goal cannot be reached with the final alone. A student at 78% with a final worth 20% who wants 90% would need 138% on the final. Unless the course offers extra credit, the best case is a lower grade: the table next to the answer shows what each common goal (90, 80, 70, 60) needs, so you can see which one is still open. Ask the instructor whether extra credit, a dropped lowest score, or a replacement policy (the final replacing a weaker midterm) exists — those change the weights, and this calculator only knows the weights you type.
What if the number is negative or zero?
The goal is already secured. A student at 96% with a final worth 15% who wants 90% gets 56% as the requirement, which is below zero: even a zero on the final leaves the course grade above 90%. A zero is still a possibility to avoid in practice, because some courses require passing the final on its own, regardless of the course average. That is a rule in the syllabus, not arithmetic.
How do I use total points instead of percentages?
Many courses add up points rather than weights. Enter the points you have earned so far, the total points in the whole course (final included) and the points the final is worth. Example: 640 points earned, a 1,000-point course, a 200-point final and a goal of 80%. Eighty percent of 1,000 is 800 points, so you need 160 more, which is 80% of the final. The course range at this moment runs from 64% (zero on the final) to 84% (a perfect final).
How is this different from the grade calculator or weighted average calculator?
The grade calculator on this site builds your current grade from categories (homework, quizzes, tests) and then offers a final-exam mode. The weighted average calculator is a general-purpose tool for any values and weights. This page starts from the grade you already have and focuses on the final: it supports a points mode, shows the requirement for every common goal at once, and lists what each final score would do to your course grade.
What if I do not know my current grade before the final?
Work it out first from your gradebook: add the weighted contributions of every graded category and divide by the share of the course that has been graded so far. If homework is 20%, quizzes 30% and the midterm 20%, the graded part is 70% of the course and the 'current grade' to type here is the weighted result divided by 0.70. If your learning system already shows a running percentage, check that it counts only graded work; some platforms treat ungraded items as zero.
Does rounding matter?
It can. Some instructors round 89.5 to 90, others do not round at all, and some round only the final course grade. The calculator gives the exact figure for the goal you type. If you need 89.5% for an A because the instructor rounds up, type 89.5 as the goal. The policy is in the syllabus; the arithmetic cannot know it.
The calculator is plain arithmetic on the numbers you enter; there is no outside data. Your syllabus and your instructor decide rounding, dropped scores, extra credit and the grading scale. Related: the grade calculator (current grade from categories), the GPA calculator, the weighted average calculator and the percentage calculator. How we check our calculators.