Final Grade Calculator

What you need on the final for an A, B, C or D

For a current grade and a final weight, the score each letter grade needs, on the common 10-point scale: A = 90, B = 80, C = 70, D = 60. Your school’s cutoffs may differ. The table fills in with your own numbers as you type them above.

In the example, an A would take 114%, which is out of reach: with 100% on the final that student finishes at 86.5%, a B. “Over 100%” means the final alone can’t get you that grade, and “Any score” means even a 0 on the final keeps it.

How to calculate the grade you need on your final

Final needed = (goal − current × (1 − weight)) ÷ weight(1)

Write the weight as a decimal: a final worth 20% is 0.2. Your current grade covers the other 80% of the course, so it has already banked current × 0.8; the final has to supply the rest of your goal. With 92% now and a goal of 90%: 92 × 0.8 = 73.6 banked, 90 − 73.6 = 16.4 still needed, and 16.4 ÷ 0.2 = 82% on the final.

Run it the other way once you have your score: course grade = current × (1 − weight) + final × weight. Scoring 75 on that 20% final gives 73.6 + 15 = 88.6%. Either way it is a weighted average of two parts, your work so far and the final, which is why the calculator’s check line multiplies your score back and adds it to what you have banked.

What if you need more than 100% on the final?

Then the goal can’t be reached through the final alone. With 83% now and a final worth 20%, a 90% would take 118%. A perfect score gets you 66.4 + 20 = 86.4%, and the calculator shows that figure rather than an impossible one.

Extra credit or a curve are the only other routes, if your course offers them. Otherwise the useful question is the next grade down: the table above shows it for your numbers — a B from 83% with a 20% final takes 68%.

The lowest score you can get on the final and keep your grade

Sometimes the answer is nothing at all. With 95% now and a final worth 10%, an 80% is already secured: even a 0 on the final leaves you at 85.5%. The calculator says “already secured” instead of printing a negative score.

To pass, set the goal to your course’s pass mark, which is 60% or 70% depending on the course. From 75% now with a final worth 30%, you need 25% on the final to finish with 60%, or 58.34% to finish with 70%.

How much is your final worth?

Look in the grading section of your syllabus, in high school or college alike: it may say “Final exam 20%”, or give the final’s share of the course’s points. Each course sets its own weight. For a course graded in points, divide the final’s points by the course total: a 200-point final in a 1,000-point course is worth 20%, so enter 20.

Two limits are worth knowing. A final worth 100% means your current grade doesn’t count: you need your goal itself on the final. And a final worth 0% can’t change your grade, so there is nothing to work out.

Why the score you need is rounded up

The score you need is the lowest one that reaches your goal, so it is rounded up, never to the nearest. From 75% with a 30% final, a 70% takes 58.333…%. Rounded to the nearest, that is 58.33 — and 52.5 + 58.33 × 0.3 = 69.999, just short of 70. The calculator shows 58.34%, and its steps show the unrounded figure first so you can see the rounding.

It also never rounds a score below 100 up to 100: when you need 99.998…%, it shows 99.999% rather than a perfect score you don’t need. Whether your school turns an 89.5 into an A is its own rule, not arithmetic — some do; check before counting on it.

Don’t know your current grade?

Use the grade your course portal shows for the work done so far. Some portals show two figures — a “current” grade over graded work only, and a “total” that counts ungraded work as 0 — and the current one is the figure to enter here.

The calculator assumes your current grade covers everything in the course except the final. If some work is still to come, such as a project or a last quiz, the answer is only as good as that assumption; dropped scores the portal already leaves out are fine.

If your syllabus weights categories — homework 20%, quizzes 30%, tests 50% — work out the current grade first with the weighted grade calculator, then bring it back here.

What your syllabus may change

The arithmetic is the same everywhere; the rules around it are your course’s. Check the syllabus for the details that may change your answer:

• Cutoffs. Some schools put an A at 93 rather than 90, and some use plus and minus grades. Set the goal to your school’s cutoff.
• Rounding. Some courses round an 89.5 up to 90; others don’t.
• Dropped scores. Some courses drop your lowest test, and some let the final replace one. Either changes your current grade.
• Curves. A curve may move the final’s score or the course grade after the fact. The calculator works before any curve.