How to calculate weighted grades
If a worksheet asked you to show work, start with the steps: convert weights, multiply by scores, add, divide. The calculator under the steps uses the same math so you can check a pencil pass without hunting another site.
GRADE CATEGORIES
Name · score · share of course
COURSE PERCENT
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Enter numbers and calculate.
Planning math only — not your school gradebook
When to use — and when not to
When to use
Homework says “show how you weighted the grade”; parent night; you get averages but not weights.
When not to
You already know the steps and just need rows fast — weighted grade calculator. Equal weights only — grade average calculator.
Assumptions
Percents in, percents out. Convert points to % before weighting unless every row shares one point pool.
How it works
contribution_i = score_i × (weight_i / 100) course% = Σ contribution (or normalize by Σ weight)
- Write each category score as a percent.
- Write each weight as a percent from the syllabus.
- Multiply score × weight for each row (keep weight as percent or decimal — be consistent).
- Add products; if weights ≠ 100, divide by total weight.
- Check with the calculator below.
Examples
88 @ 30%, 76 @ 70%
26.4 + 53.2 = 79.6%
100 @ 10%, 80 @ 20%, 70 @ 70%
10 + 16 + 49 = 75%
Gotchas
- Using 20 instead of 20% without converting will blow up the sum.
- Credits for GPA are a different problem — see the GPA pages.
- Mid-term missing categories: either omit and normalize or solve for the empty row.
Compare
Calculator-first layout? Weighted grade calculator. “Calculating grades by weight” wording? That sibling page.
See also: weighted grade calculator, calculating grades by weight, and grade calculator with weights.
Related
FAQ
Multiply each score by its weight, add, divide by total weight.