Grade Calculator

Combine weighted marks — or find the score you need on the final.

How the calculator works

Weighted grading multiplies each item's score by its weight and divides the sum by the total weight used, so results stay correct even when you have only completed part of the course — an 88% midterm worth 30% contributes 26.4 points, not 88. The final-exam mode solves the equation target = current × (1 − w) + exam × w for the exam score, where w is the final's weight. If the required score is negative, any exam result — even zero — keeps you above target; if it exceeds 100, no legal score reaches the target and the result says so instead of showing an impossible number.

Formula

Overall = Σ (score × weight) ÷ Σ weight
Needed = (Target − Current × (1 − w)) ÷ w

Where:

  • score / weight — each item's percentage and its share of the grade
  • Current — your grade before the final exam
  • w — the final exam's weight as a decimal (40% = 0.40)
  • Target — the course grade you want to end with

Example

Suppose you have scored 82% on homework worth 20%, 78% on labs worth 20%, and 74% on the midterm worth 30%. The weighted average is (16.4 + 15.6 + 22.2) ÷ 0.70 = 77.4% so far. With a final worth the remaining 30% and a target of 80%, you need (80 − 77.4 × 0.70) ÷ 0.30 ≈ 86% on the exam — demanding but achievable, and knowing the exact number beats guessing.

Frequently Asked Questions

The weights I've entered don't add to 100%. Is the result wrong?
No — the calculator divides by the weights you actually provided, so an in-progress course is handled correctly. The result row shows the total weight used; when it reads 100%, you are seeing the complete course grade.
Can I include extra credit?
Add it as another row with its score above 100 only if your syllabus allows scores above 100; otherwise fold extra-credit points into the item they belong to before entering the score. The math follows your syllabus, not the other way round.
What if my final is a two-part exam?
Enter each part as a separate weighted row in the weighted mode. A written part worth 25% and a practical worth 15% behave exactly like two independent items in the overall calculation.
My school grades out of 20/100/GPA. Can I still use this?
Yes, as long as you convert marks to percentages first: divide by the maximum and multiply by 100. Percentage is the common denominator every grading system shares, which is why this calculator speaks it.