A worked example, in full
Suppose a course weights homework at 20% and a midterm at 30%, with the rest — quizzes and the final — not graded yet. You scored 90% on homework and 75% on the midterm.
| Category | Score | Weight | Score × weight |
|---|---|---|---|
| Homework | 90% | 20% | 1800 |
| Midterm exam | 75% | 30% | 2250 |
| Total (graded so far) | 50% | 4050 |
Weighted grade so far = 4050 ÷ 50 = 81.0%. Note what did not happen: the ungraded 50% of the course was not treated as zero. Dividing by the weight actually graded (50) rather than by 100 is called normalising, and it is what most grade books show mid-course.
Then why does the zeros number exist?
Divide the same 4050 by 100 instead and you get 40.5% — that is not a current grade, it is a floor: the grade you would finish with if you scored zero on everything remaining. Both numbers are useful; mistaking the floor for your current grade is the classic weighted-grade panic. As each remaining category is graded, the two numbers converge, and when the weights entered reach 100% they are identical. The weighted grade calculator shows both side by side for exactly this reason.
Weighting inside a category
Categories have internal maths too. A "tests" category worth 40% might average three tests equally (each effectively 13.3% of the course) or weight them by points. When a teacher says a category is "averaged", unweighted inside the category is the usual meaning; when they say "points-based", every assignment in the whole course is effectively one big points pool and category weights are an approximation. If your grade book shows points, the points grade calculator converts any single score.
Common course structures (examples, not standards)
| Course type | Typical weighting |
|---|---|
| Lecture course, heavy final | Homework 10% · Quizzes 10% · Midterm 30% · Final 40% · Participation 10% |
| Lecture course, balanced | Homework 20% · Quizzes 15% · Midterm 25% · Final 30% · Participation 10% |
| Lab science | Homework 15% · Quizzes 10% · Midterm 20% · Final 25% · Lab work 30% |
| Writing / humanities | Papers 30% · Midterm 20% · Final 25% · Participation 25% |
These are illustrations of how syllabi are commonly arranged, nothing more — your course's actual weights are whatever your syllabus says, and they are what you should type into the calculators on this site.
Frequently asked questions
Do weights have to add up to 100%?
In a complete syllabus, yes (extra credit aside). Mid-course, the graded weights add to less — which is exactly when normalising matters.
Is a weighted grade the same as a points grade?
Only when weights happen to match point shares. A 10-point quiz and a 200-point final averaged "equally" as categories is a different course from one where they pool 210 points. Ask your teacher which system the course uses if the two give different answers.
How does the final exam fit into this?
The final is one more category. Once you know your weighted grade without it and its weight, the final grade calculator solves for the score you need; the algebra is derived on the formula page.