Grade average calculator
Calculate simple and weighted averages from scores.
The grade average calculator takes a list of scores with optional weights and computes both a simple average (equal weight per row) and a weighted average (Σ(score × weight) ÷ Σweight) side by side, so you can see how weighting changes the result.
Valid rows
3
Total
260.00
Simple average
86.67
Weighted average
85.40
How to use
- Add a row per assignment, quiz, or exam, with a score and an optional weight.
- Rows with a blank score are ignored entirely; rows with a blank or zero weight still count toward the simple average, just not the weighted one.
- Weighted average = Σ(score × weight) ÷ Σweight.
Common use scenarios
- Averaging quiz and exam scores across a term.
- Checking whether a weighted grading scheme changes a student's overall grade.
- Averaging scores where some assignments count more than others.
- Double-checking a gradebook's calculated average by hand.
✓Content & verification reviewed: 2026-08-25
How we verify Grade average calculator
How to confirm the two averages reflect the calculation you intend.
Blank scores are ignored entirely; blank or zero weights are not
A row with no score doesn't count toward either average at all, but a row with a score and a blank or zero weight still counts toward the simple average — it's only excluded from the weighted average — so the two averages can legitimately be based on a different number of rows.
Weighted average = Σ(score × weight) ÷ Σweight
The weighted average multiplies each valid row's score by its weight, sums those products, and divides by the sum of the weights — rows with zero or blank weight contribute nothing to either the numerator or denominator of this calculation.
No weighted average shows if no row has a positive weight
If every row's weight is blank or zero, the tool can't compute a meaningful weighted average and shows a notice instead of a misleading number like zero or the simple average repeated.
Before you rely on the result
- Every score you intend to include is filled in — a blank score row is skipped entirely.
- You understand rows with blank/zero weight still count in the simple average but not the weighted one.
- If you expected a weighted average and got a notice instead, you've checked that at least one row has a positive weight.
- You've compared the simple and weighted averages to confirm the weighting is producing the effect you expect.
Who this is for
- Teachers averaging quiz and exam scores across a term.
- Anyone checking whether a weighted scheme changes an overall grade.
- People averaging scores where some assignments count more than others.
- Anyone double-checking a gradebook's calculated average by hand.
Real-world examples
Term grade check
A teacher enters every quiz and exam score with weights matching the syllabus (exams worth more than quizzes) to confirm a student's final weighted grade before entering it in the gradebook.
Comparing simple vs. weighted
A teacher curious whether weighting exams more heavily changes a borderline student's grade enters the same scores with and without weights to see both averages side by side.
Spot-checking a gradebook
Someone who doesn't fully trust their spreadsheet's average formula re-enters the same scores here to confirm the calculated average matches.
Limitations
- Rows with a blank or zero weight are excluded only from the weighted average — that's intentional, not a bug, if the two numbers look different.
Frequently asked questions
What happens to a row with no score entered?
It's ignored entirely — it doesn't count toward either the simple or weighted average, unlike a row with a score but no weight.
Does a blank weight count as zero?
For the simple average, a row with a blank or zero weight still counts equally with every other row. For the weighted average, both are excluded the same way — they contribute nothing to the weighted calculation.
Why don't I see a weighted average?
That happens when no row has a positive weight — with nothing to weight by, the calculation isn't meaningful, so the tool shows a notice instead of a number.
What's the exact weighted average formula?
It's the sum of each row's score multiplied by its weight, divided by the sum of all the weights — Σ(score × weight) ÷ Σweight.
🔒 Runs in your browser — nothing is uploaded. Results are for reference only; see the disclaimer. Last updated: 2026-08-25
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