How to use this calculator
- Enter or choose final exam weight.
- Enter or choose target course grade.
- Add a grade and credits for each course; leave unused rows blank.
- The current weighted grade updates as you type. Use Copy result or Share to keep it.
Method
Current grade = Σ(score × weight) ÷ Σ weight; Final needed = (Target × (Σ weight + Final weight) − Σ(score × weight)) ÷ Final weight
- score
- percentage on each item
- weight
- share of the course grade for that item
- Target
- course grade you want
Worked example
- Weighted points: 88 × 20 + 76 × 30 + 92 × 10 = 1,760 + 2,280 + 920 = 4,960.
- Current grade = 4,960 ÷ 60 = 82.67%, a B− on the common US scale.
- For 85% overall across 60 + 40 = 100 weight: 85 × 100 = 8,500 points, so the final must supply 8,500 − 4,960 = 3,540.
- Final needed = 3,540 ÷ 40 = 88.5%.
With 82.67% on 60% of the course, you need 88.5% on a final worth 40% to finish with 85%.
What the result means
Weights do not need to add up to 100: the current grade is averaged over the weight graded so far. If the score needed on the final is above 100%, the target cannot be reached without extra credit.
Assumptions and limits
- Scores are percentages and weights are shares of the final course grade.
- Letter scale: A+ 97+, A 93+, A− 90+, B+ 87+, B 83+, B− 80+, C+ 77+, C 73+, C− 70+, D+ 67+, D 63+, D− 60+, F below 60.
- Courses that drop the lowest score, curve grades or use points instead of weights need the scores converted first.
Questions
My items are in points, not percentages. What do I enter?
Convert each to a percentage (points earned ÷ points possible × 100) and use the item’s share of the course as its weight.
Why does my letter grade differ from my school’s?
Cut-offs vary between schools and countries. The letter shown uses a common US scale; your syllabus has the one that counts.