How your current grade is worked out
A class rarely marks everything the same way. A quiz might count for a tenth of the final grade, a midterm for a quarter, a project for another quarter, and homework for the rest. Treating every one of those the same, a plain average of the scores, would let a low-stakes quiz drag the total down exactly as hard as a midterm that was meant to matter three times as much. The fix is a weighted average: multiply each score by its own weight before adding, then divide by the total of the weights rather than by a plain count of assessments.
Weight here almost always means a percentage of the course, the share your syllabus puts against that piece of work. Score is whatever you were actually marked, out of 100. Multiply the two, add every assessment's result together, then divide by however much weight you have actually entered so far, not by an assumed total of 100. That last part matters more than it sounds: a class only two-thirds of the way through the term has weights that add to less than 100, and the arithmetic still works correctly as long as you divide by what has genuinely been assigned so far rather than a fixed number.
A worked example
Take four pieces of work: homework at 88% worth 20% of the grade, a midterm at 78% worth 25%, quizzes averaging 92% worth 15%, and a project at 85% worth 15%. Multiply each score by its weight: 1,760, 1,950, 1,380 and 1,275. Add those four figures and the total comes to 6,365. The weights themselves add up to 75, so divide 6,365 by 75 rather than by 100, since only 75% of the course has been marked so far. The result is 84.87%, a B on the common ten-point scale. Notice the midterm, worth the most of the four and also the lowest score, pulls the total down further than its raw percentage alone would suggest; that is exactly what a weight is meant to do.
Reading your weight total
The total weight you have entered is shown prominently above the results for a reason: it changes what the headline number actually means. If your weights add up to less than 100, the figure you get back is your grade on the part of the course marked so far, not a prediction of where you will land once everything, including a final exam, is in. If your weights add up to more than 100, the calculator still works, dividing by whatever total you entered rather than assuming 100, but it is worth checking your syllabus; a total past 100 usually means a typo or a double-counted assessment rather than a genuine grading scheme.
A weight of zero on a row is not the same as leaving it out. It keeps the assessment listed, useful for a piece of work that has not been returned yet, while contributing nothing to either side of the division until you fill in a real weight.
Letter grades, and why the boundaries move
This page reports a letter alongside the percentage using the ten-point scale taught in most American schools: 90% and above is an A, 80 to 89 a B, 70 to 79 a C, 60 to 69 a D, and anything below 60 an F. It is the most widely used default, and the one this calculator assumes when it shows a letter, but it is not universal. Some schools mark to a stricter scale where 93% is needed for an A, others split every band further into plus and minus grades, and a handful of university courses set their own boundaries entirely, sometimes moved after the fact once every student's mark is in. Treat the letter shown here as the common case, and check your own syllabus if the exact cut-off matters to you.
What do I need on the final?
The second tab answers a different, more urgent question: given a current grade, how well does the final exam need to go to reach a particular overall result? The same weighted-average equation is doing the work, just rearranged to solve for the one unknown, the final score, instead of for the overall grade.
Here, current and target are both percentages, and the final's weight is written as a share of 1, so a final worth 25% of the grade is 0.25 in the formula, even though the calculator itself takes the input as a plain 25. Take a current grade of 83.53%, a final worth 25% of the course, and a target overall grade of 90%. Plugging in: (90 minus 83.53 times 0.75) divided by 0.25 works out to 109.4%, a score the final cannot actually deliver. Lower the target to 80% instead, and the same current grade and final weight need only 69.4% on the final, comfortably within reach.
When the final can't get you there, and when it already has
Two edge cases are worth calling out on purpose rather than leaving them as an odd-looking number. A required score above 100% means the target is out of reach through the final alone, whatever mark you get; the calculator shows the best the final can actually do, current grade times the non-final share plus a full 100% on the final, so you can see exactly how close the ceiling comes to your target. A required score below 0% means the opposite: the target is already secured before the final counts for anything at all, so even a blank paper would not move you below it. Neither result is a bug in the arithmetic; both are the equation reporting, correctly, that the final exam's weight simply is not large enough to move the outcome as far as the target asks.
The table further down runs the same calculation across the standard grade boundaries, A, B, C and D, so you can see at a glance which grades are still realistically open to you and which would need more than the final alone can offer.
Choosing your inputs well
The current grade you enter on the second tab should already be weighted the way your course weighs it, not a plain average of your scores; the first tab exists to work that figure out for you; use the "Use my grade" button rather than retyping it. The final's weight is whatever share your syllabus assigns to that one exam, commonly somewhere between a fifth and a half of the overall grade, and it is worth checking the syllabus rather than guessing, since a few percentage points either way change the answer meaningfully. This page works entirely within one class; if you are instead trying to combine several courses into a single overall average across a term or a whole programme, that is a different sum built around credit hours rather than assessment weights, and a dedicated tool for that job sits among the related calculators below.
Questions people ask
Do my weights have to add up to 100?
No. The calculator divides by whatever total you have entered, so a class that is only two-thirds marked, weights adding to around 65 or 70, still gives an accurate grade for the work done so far. If your weights add up to noticeably more than 100, check your syllabus for a typo or a double-counted assessment.
Why does a low score on a heavily weighted assessment hurt more?
Because the whole point of a weight is to make one assessment count for more of the total than another. A 60% on something worth 30% of the grade drags the overall figure down further than the same 60% on something worth only 5%, exactly as your syllabus intends.
What does a letter grade of B actually mean here?
On the common ten-point scale this page uses, a B covers 80 to 89%. It is the widely taught default in American schools, not a universal rule; check your own institution if it grades to a stricter scale or splits bands into pluses and minuses.
My required final score is over 100%. What now?
It means the target is not reachable through the final alone, whatever score you get. The results show the highest overall grade a perfect final could still produce, so you can judge how close that ceiling comes and whether extra credit, a regrade on earlier work, or a more realistic target makes more sense.
My required final score is negative. Does that mean I can skip it?
It means your target is already secured mathematically; even a zero on the final would not pull you below it. It is not advice to skip an exam, plenty of courses have separate rules about missed assessments, only a statement about where the weighted arithmetic already sits.
Can I leave an assessment's weight at zero?
Yes. It keeps the row visible, useful for something not yet marked, while contributing nothing to the current grade until you fill in its real weight.
Is this the same as GPA?
No. This page works out your percentage grade inside a single class from its own assessments. A GPA combines letter grades and credit hours across several courses into one overall figure, a different calculation built around a different question.
This calculator uses the weighting and grading scale you enter or the common ten-point default; always confirm the exact figures your course actually uses against your syllabus or instructor before treating a result as final.