Grade Calculator
Work out your course grade from weighted components and what you need on the final.
About Grade Calculator
Each score is multiplied by its weight, those products are summed, and the total is divided by the sum of the weights. If your weights add up to 100, that's your final percentage grade.
Formula
Weighted grade = Σ(score × weight) ÷ Σ(weights)
- sᵢ
- Score for item i (e.g. 90 for 90%)
- wᵢ
- Weight for item i (e.g. 20 for 20% of the total grade)
- ḡ
- Final weighted grade
Worked example
With the default values below, Grade Calculator returns Weighted Grade of 82.50%. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Scores (score:weight, comma separated)
- 90:20, 85:30, 78:50
Results
- Weighted Grade
- 82.50%
- Total Weight Entered
- 100.0
Step by step
- 1Multiply each score by its weight= 8,250.00
- 2Sum of all weights= 100.0
- 3Weighted grade = weighted sum ÷ total weight= 82.50%
Assumptions and limits
- The result is derived only from the single input listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Grade Calculator — full guide
Turning a syllabus into one number
Most syllabi split a course by weight: homework 20%, midterm 30%, final 50%. This calculator takes exactly that. Enter each graded item as score:weight, comma separated — the default 90:20, 85:30, 78:50 is that syllabus with all three scores recorded. Two results come back: the Weighted Grade and the Total Weight Entered.
The arithmetic
Weighted grade = Σ(score × weight) ÷ Σ(weights). Multiply every score by its own weight, add the products, then divide by the total weight. When your weights add to 100, dividing by 100 converts the point total straight into a percentage.
Default example, step by step
- Homework: 90 × 20 = 1,800
- Midterm: 85 × 30 = 2,550
- Final: 78 × 50 = 3,900
- Products added: 1,800 + 2,550 + 3,900 = 8,250
- Weights added: 20 + 30 + 50 = 100
- 8,250 ÷ 100 = 82.5%
Two of the three scores beat 82.5, yet the total still lands below the midterm mark, because the 78 carries half the course on its own. That asymmetry is the whole point of weighting.
Mid-semester, before the final
Enter only 90:20, 85:30. Total Weight Entered reads 50 and the grade is (1,800 + 2,550) ÷ 50 = 87%. Read that as your standing across graded work so far, covering half the course — not as a projected final grade. The weight total is the honest caveat attached to the percentage.
Working backwards to a target
With 4,350 points banked and a 50-weight final outstanding, the score needed for an overall target T is (T × 100 − 4,350) ÷ 50:
| Target | Needed on the final |
|---|---|
| 85% | 83 |
| 90% | 93 |
| 95% | 103 — not reachable |
Anything above 100 means the target is gone unless extra credit exists.
Mistakes that change the answer
- Entering raw points instead of percentages. An 18-out-of-20 quiz is
90:10, not18:10. Convert first. - Forgetting a dropped score. If the syllabus drops your lowest quiz, omit that item; the division by the remaining weight total rebalances the rest automatically.
- Treating weights as points earned. The weight is the share of the course, not the marks available.
- Expecting curves. Instructor curves, attendance bonuses and the rounding rule that turns 89.5 into an A are applied by your institution, not here.
Extra credit fits naturally — a 105:10 bonus item is allowed and will pull the total above the raw scores.
To roll several finished courses into one figure, move to the GPA Calculator. Use the Percentage Calculator to convert marks out of an odd total, and the Average Calculator when every item carries equal weight.
Frequently Asked Questions
Do my weights need to total 100?
Not necessarily — the calculator divides by whatever the weights sum to, so relative weights work too. But for a true final grade, they should total 100%.
What grade do I need on the final?
Enter your known scores and weights, then add the final exam with its weight and try different scores to see the grade each would produce.
My syllabus drops the lowest quiz score — how should I enter that?
Leave the dropped quiz out of the list. Because the result divides by whatever weight you entered, the surviving items keep their relative sizes and absorb the gap. Four 5-point quizzes with one dropped become three entries of 5 weight each, and the total weight you see drops from 100 to 95.
Can I add extra credit that pushes a score above 100?
Yes. Scores are not capped, so a bonus project marked 105 goes in as 105 with its weight. Added to the default list as 105:10, the total weight becomes 110 and the grade rises from 82.5 to about 84.5 (9,300 ÷ 110). If your institution caps the final grade at 100, apply that cap yourself afterwards.
My weights only add to 50 — is the 87% I got my current grade?
It is your average across the work graded so far, weighted correctly among those items. It is not your course grade, because the remaining 50 weight is still unknown. Treat 87 as a running mark and use the target arithmetic to see what the final needs to be: 83 for an 85 overall.
The items in my syllabus are given as points, not percentages — what do I enter?
Either convert both to percentages, or use points as the weights. Homework worth 200 of 1,000 course points with 180 earned goes in as 90:200, since 180/200 = 90%. Keep one convention across the whole list; mixing a percentage weight with a points weight silently rescales the course.