Final Grade Calculator

How to use this tool

Pick what to calculate. "Score needed on the final" takes your grade so far, the final's weight and a target, either a percent or a letter. "Course grade from a final score" runs the other way. "Needed score from categories" suits syllabi that list weights for assignments, quizzes and a midterm, with up to six rows and the final taking the weight that is left. "Score needed for every letter" lists A to D at once. Cutoffs start at the common US 90, 80, 70 and 60, so match them to your syllabus, and raise the highest possible score if the final has bonus marks.

The input people most often get wrong is the grade so far. It is your average on the work already graded, out of 100, not the points you hold out of the whole course: 55 points from work worth 70 is 78.57, not 55. The second slip is the weight, the share of the whole course the final carries, so a 25% final goes in as 25. Work still to come, such as participation, is counted inside the final's share in category mode, so add a row for it if you can estimate it.

What the calculation is doing

A course grade is a weighted average. Let c be your grade so far, w the final's weight as a decimal and f your final score. The course grade is c × (1 − w) + f × w. The first term is what you have banked, c on the share of the course already graded, and the second is what the final adds.

Solving for f gives f = (T − c × (1 − w)) ÷ w, where T is the target. Subtract the banked points from the target to see what the final must supply, then divide by w, because each exam point is worth only w points of course grade. With c = 78, w = 0.25 and T = 80, you have 58.5 banked, the final must supply 21.5, and 21.5 ÷ 0.25 is 86. An easier form to hold in your head is f = c + (T − c) ÷ w: your average plus the shortfall divided by the weight.

Two results get special treatment. If the score needed is above the highest possible on the final, 100 unless you change it, the target is out of reach and the page says so. If it is zero or below, a zero on the final still keeps the target and the page reports it as already safe. In category mode the grade so far is the sum of weight times grade over the sum of the weights, and the final takes the remainder.

Why the weight of the final drives everything

In f = c + (T − c) ÷ w the gap between your average and your target is divided by w. With a final worth 20%, every point of course grade you still need costs 5 exam points, since 1 ÷ 0.20 = 5. At 25% it costs 4, at 30% it costs 3.33 and at 40% it costs 2.5. Being 2 points short of a B on a 25% final means beating your current average by 8 points.

Set the exam score to 100 and solve for the average, and you get the point of no return, c = (T − 100 × w) ÷ (1 − w). For a target of 90 it is 88.2 with a 15% final, 87.5 with 20%, 85.7 with 30% and 83.3 with 40%. Below those averages, even a perfect final falls short. The diagram plots all four lines, and they meet at one point: a student whose average equals the target needs exactly the target, whatever the weight.

Left of that meeting point a heavier final is kind to you. With 85 so far, an A needs 110 on a 20% final, which cannot be done, and 97.5 on a 40% final, which just can. Right of it the effect flips. With 95 so far, an A needs 70 on a 20% final but 82.5 on a 40% final, because a heavier final puts more of your banked lead at risk.

The safe zone follows the same logic. A zero on the final leaves you with c × (1 − w), so a target is safe once c is at least T ÷ (1 − w). A C at 70 is safe with an average of 87.5 on a 20% final, but on a 30% final only a perfect 100 guarantees it.

Weighted categories, points and what instructors change

Most syllabi use one of two systems. Weighted categories give each type of work a percentage, and you average within each category before combining them by weight. Category mode does that for the work so far and hands the leftover weight to the final. A University of Calgary tip sheet on calculating grades uses this method: two assignments worth 15 each, a midterm worth 20 and an essay worth 20 leave 30 for the final, and a goal of 80 needs 83.33% on it.

Points based grading skips the percentages. Every item has a point value, and your grade is points earned divided by points possible. The points still needed are the target percent times the total points, minus the points earned. A MiraCosta College guide, with an A at 900 points and a 200 point final, works one example: 730 points earned needs 900 − 730 = 170 more, which is 85% of 200. Enter 91.25 as the grade so far (730 of 800) and 20 as the weight, and the tool shows the same 85%.

Then there is what the arithmetic cannot see. If the final has extra credit, raise the highest possible score and a target that was out of reach may return. Some instructors round 89.5 up to 90, while this tool applies your cutoffs to the two decimal figure it shows. Some drop the lowest quiz, curve the results or require a pass on the final whatever the average says. Your syllabus decides, so treat the answer as a floor to aim above.

Score needed for an A, B or C at a 20 or 30 percent final

Each cell is the score needed on the final for the grade so far in the left column, with the standard cutoffs. Over 100 means out of reach, safe means a zero still keeps the letter, and each figure opens the calculator.

Score needed on the final, in percent, with cutoffs of 90, 80 and 70. The heading shows the letter and the weight of the final.

The options disappear quickly. At 75 so far, a B needs a perfect 100 on a 20% final but 91.7 on a 30% one, and an A is out of reach either way. At 65, even a C needs 90 on a 20% final. A 90 average makes a C safe at 20% but still needs 23.3 at 30%.

A worked example you can check on paper

Take the starting values: 78% so far, a 25% final and a B, which is 80%. The rest of the course is 100% − 25% = 75%, so you have banked 78 × 0.75 = 58.5 points. A B needs 80, so the final must supply 80 − 58.5 = 21.5, and 21.5 ÷ 0.25 = 86%. Check: 58.5 + 86 × 0.25 = 80. The short form agrees: 78 + (80 − 78) ÷ 0.25 = 86.

At the same inputs an A needs (90 − 58.5) ÷ 0.25 = 126%, which is out of reach, a C needs 46% and a D needs 6%. A zero on the final leaves you at 58.5% and a perfect one at 83.5%, so a B is the highest letter still in reach.

Category mode starts with the Calgary tip sheet's numbers: 80 on two assignments worth 15% each, 75 on a midterm worth 20% and 80 on an essay worth 20%. Points so far are 12 + 12 + 15 + 16 = 55 out of 70, an average of 78.57%. The final takes the remaining 30%, a goal of 80 leaves 25 points to earn, and 25 ÷ 0.30 = 83.33%, the figure the tip sheet gives.

Mistakes that catch people out

Entering points as a percent. Fifty five points out of 70 graded so far is 78.57%, not 55. Divide first, because the tool needs your average on the graded work.

Mixing up the weight. A final worth 25% of the course goes in as 25, and a 100 point exam in a 400 point course is 25%. Typing 0.25 tells the tool the final is a quarter of one percent.

Leaving out work still to come. Participation, lab reports or a project with no grade yet are part of the rest of the course. In category mode they join the final's share, so estimate them in a row or the answer will not mean what you think.

Trusting a rounded letter. A course grade of 89.6% is a B here, because the cutoff is applied as entered. Some instructors round up and some do not, so ask before you rely on a fraction of a point.

Planning to score exactly the number shown. The needed score is the least that works. Aim several points above it, and remember that a needed score near 100 leaves no room for a single slip.

Popular calculations

Each link opens the calculator with the figures filled in, and every value can be changed once it is open.

Score needed for an A

Score needed for a B

Score needed for a C

What if I score this on the final

From your categories

Every letter at once

Extra credit and custom cutoffs

How this was checked

The engine was compared with four published worked examples. A University of Calgary tip sheet, with weights of 15, 15, 20 and 20 and a 30% final, reaches 83.33% for a goal of 80, and the tool matches it. A MiraCosta College guide, with 730 points earned, an A at 900 and a 200 point final, gets 85%, and the tool reproduces it. A University of Illinois weighted components example totals 84.955 and a B, matched exactly, and a Northern Arizona University example, (0.35 × 85 + 0.40 × 90) ÷ 0.75 = 87.67, matches too.

Independent checks followed. Across 96,240 combinations of grade so far, target and weight, the course grade from the needed score equalled the target to better than a trillionth of a point, and a separate bisection search agreed on the score and the out of reach or safe verdict every time. Category mode matched a separately coded integer weighted average on 3,000 random tables. A weight of 100 returns the target, a weight of 0 is refused, and weights reaching 100 leave nothing for the final. Every address in the lists above was opened and checked for a distinct title, the right answer, working charts, and clean CSV, image and print output, at desktop, tablet and phone widths.

Common questions

How do I calculate what I need on my final exam?

Subtract your banked points from the target and divide by the final's weight. With 78% so far, a 25% final and a target of 80, that is (80 − 78 × 0.75) ÷ 0.25 = 86%. The shortcut is your average plus the shortfall divided by the weight: 78 + 2 ÷ 0.25.

What if the score needed is over 100%?

The target is out of reach on the exam alone, because even a perfect final leaves you short. The tool shows the best you can finish with and the highest letter still in reach. If the final carries extra credit, raise the highest possible score. Otherwise the useful move is a lower target, or asking your instructor about a curve or a dropped score.

What does a needed score of zero or less mean?

The target is already safe. With a 90% average and a 20% final, a zero on the final still leaves you at 72%, so a C at 70 is secure. Check the syllabus first, because many courses require a passing mark on the final whatever the average.

What score do I need on the final to pass the course?

Set the target to the passing grade as a percent, commonly 50 or 60, or read the D row in the letter table. With 55% so far and a 30% final, a target of 60 needs (60 − 55 × 0.7) ÷ 0.3 = 71.67% on the final. The same arithmetic works for any passing mark your school uses.

How does the weight of the final change the score I need?

Below your target, a heavier final lowers the score you need, because the gap is spread over more of the course. Above it, a heavier final raises the score, because more of your lead is at risk. With 85 so far and an A as the goal, finals of 20%, 30% and 40% need 110%, 101.67% and 97.5%. With 95 so far they need 70%, 78.33% and 82.5%.

Can I use this for points based grading?

Yes. Your grade so far is the points earned divided by the points possible so far, and the weight is the final's points divided by the course total. Or work in points directly: points needed = target percent × total points − points earned. In a 500 point course with 340 points earned, a B needs 0.80 × 500 − 340 = 60 more points.

Related Calculators and Reference

• Test Score Calculator: turn a raw mark into a percent and a letter before you enter it here.
• GPA Calculator: see what the letter you are aiming for does to your grade point average.
• Weighted Average Calculator: the same weighted mean for any other set of scores and weights.
• Percentage Calculator: percent of a number and percent change, for points based courses.
• Z Score Calculator: how far a mark sits from the class average when a course is curved.
• University of Calgary tip sheet on calculating grades: a worked weighted example with a final exam goal.