How the grade calculator works
Most classes do not treat every assignment equally: a midterm worth 25% of your grade matters five times more than a quiz worth 5%. Your course grade is therefore a weighted average, where each score is multiplied by its weight before anything gets averaged. This calculator does that for every row you fill in and skips the blank ones, so it works just as well three weeks into the semester as it does at the end.
It also shows its working. Every result walks through the same arithmetic the answer came from, line by line, with your own numbers in it. That is deliberate: a number you cannot check is a number you have to take on faith, and this is the one subject where you should never have to.
The formula
Multiply each score by its weight, add up those products, then divide by the total weight you entered. When your weights add up to exactly 100, the denominator is simply 100.
Worked example
Say you are two thirds of the way through a class. Homework is 92% and worth 20, quizzes are 84% and worth 15, and the midterm was a 78% worth 25:
Grade = (92 × 20 + 84 × 15 + 78 × 25) ÷ (20 + 15 + 25) = 5,050 ÷ 60 = 84.17%, a B on the plus / minus scale.
Note what that 84.17% is and is not. It is your standing on the 60% of the course that has been graded. It is not your final grade, because 40 points of weight have not happened yet.
Which grading scale is yours?
Almost every grade calculator online picks one scale and never mentions it, which is how the same 84% comes back a B on one site and a B on another that happens to mean something different. Scales genuinely differ, so this one asks. Three cover nearly every US school:
| Scale | A | B | C | D | Typically used by |
|---|---|---|---|---|---|
| Plus / minus | 93+ | 83+ | 73+ | 63+ | Most colleges and universities |
| Straight 10-point | 90+ | 80+ | 70+ | 60+ | Most US high schools |
| 7-point | 93+ | 85+ | 77+ | 70+ | Traditional high school scale, still common in the South |
The gap is not small, and it lands exactly where you care most. A 91% is an A- on the plus / minus scale, a plain A on a straight 10-point scale, and a B on the 7-point scale. One number, three different letters, and the only thing that decided it was a line in a syllabus.
It reaches all the way down to passing, too. A 69.5% is a D+ on the plus / minus scale and a D on the 10-point scale, but on the 7-point scale it is an F, because that scale puts the passing line at 70 rather than 60. If you are anywhere near a boundary, the scale is not a detail.
Weights do not have to add up to 100
This is the most useful thing to know about grade math mid-semester. If only 60 points of weight have been graded, enter only those, and the calculator divides by 60 rather than by 100. That gives your real standing on the work that has actually been scored, which is a genuine answer. The alternative approaches both lie to you: treating ungraded work as zeros makes you look doomed, and ignoring it entirely makes you look finished.
Where your grade is actually being decided
Every result includes a column called points it adds, which is that assignment's grade multiplied by its weight and divided by the total. It answers a question the headline number cannot. In the worked example above, the 92% in homework contributes 30.67 points and the 78% midterm contributes 32.50, so the assignment you did worst on is still doing more of the work than the one you did best on. That is not bad news, it is a map. Weight is where the leverage lives, and knowing which row carries it tells you exactly where an hour of studying is worth the most.
What is still reachable
Fill in the optional weight of work not yet graded field and the calculator turns around and solves the other direction: for every letter on your scale, what the remaining work has to average to get you there. This is usually the question behind the question. Somebody checking their grade in week ten is rarely curious about the past; they want to know what is still on the table.
Some rows will come back reading more than 100%, and that is worth seeing rather than being spared. A goal that the remaining work cannot reach on its own is not a verdict on you, it is just arithmetic, and it is far better to find out in week ten than in week fifteen. It also turns a vague worry into a specific errand: ask about extra credit, ask whether the lowest quiz gets dropped, ask whether the final replaces the midterm. Those conversations go better when you can show the numbers.
Why your school portal may show something different
If this calculator and your grade portal disagree, the gap is almost always a class policy rather than a mistake in the math. The usual suspects: a dropped lowest quiz, assignments entered but not yet scored, extra credit sitting in a category you did not enter, a final that replaces a midterm if it is higher, or rounding applied only at the very end. Rounding especially is a policy and not a fact. Some teachers round 89.5 up, some truncate, and some round only the final course grade. If you are sitting on a borderline number, your syllabus has the answer and this calculator does not.