How to use this calculator
Choose what you want to work out.
My weighted grade. For each category, such as homework, quizzes, midterm or projects, enter your average score and the category’s weight from the syllabus. Three categories are shown; open More categories for up to six. Categories with a weight of 0 are ignored. The result is your weighted percentage and letter grade, with a table showing how many points each category contributes.
What I need on the final. Enter your current grade in the class, how much the final exam counts, and the grade you want to finish with. You’ll see the score you need on the final, the best and worst grades still possible, and a table of the final exam score needed for every letter grade from A+ to D−.
The formulas
A weighted grade is a weighted average. Each score counts in proportion to its weight:
The final exam score you need comes from rearranging that formula. Your current grade fills 1 − w of the course and the final fills w:
Here w is the final exam’s weight as a decimal: 25% is 0.25.
Worked examples
Weighted grade. Homework averages 90% and is worth 20%, quizzes average 85% and are worth 30%, and exams average 78% and are worth 50%.
- Multiply each score by its weight: 90 × 0.2 = 18, 85 × 0.3 = 25.5, 78 × 0.5 = 39.
- Add: 18 + 25.5 + 39 = 82.5.
- The weights total 100%, so the grade is 82.5%, a B−. You’re half a point from a B.
If the exams haven’t happened yet, enter only the first two categories. The weights then add up to 50%, and your grade so far is (18 + 25.5) ÷ 0.5 = 87%, a B+.
Final exam needed. You have 84% going into a final worth 25%, and you want an 85%.
- Everything before the final counts for 100% − 25% = 75%.
- You’ve banked 84 × 0.75 = 63 points.
- The final must supply 85 − 63 = 22 points.
- The final is worth 25 points in total, so you need 22 ÷ 0.25 = 88%.
Some quick checks with other numbers: with 92% going into a final worth 20%, you need 82% to keep an A− (90%). With 78% and a final worth 40%, you need 83% to reach a B− (80%). With 88% and a final worth 30%, an A (93%) would take about 104.67%, which isn’t possible without extra credit.
What you need for each letter grade
For the example above (84% current grade, final worth 25%), this is the table the calculator produces:
| Letter grade | Course grade of at least | Score needed on final | Outlook |
|---|---|---|---|
| A+ | 97% | 136% | Above 100% |
| A | 93% | 120% | Above 100% |
| A− | 90% | 108% | Above 100% |
| B+ | 87% | 96% | Possible |
| B | 83% | 80% | Possible |
| B− | 80% | 68% | Possible |
| C+ | 77% | 56% | Possible |
| C | 73% | 40% | Possible |
| C− | 70% | 28% | Possible |
| D+ | 67% | 16% | Possible |
| D | 63% | 0% | Secured |
| D− | 60% | 0% | Secured |
“Secured” means you’d reach that grade even with a zero on the final.
How much can the final move your grade?
The heavier the final, the wider the range of outcomes. Starting from an 85% in the class:
| Final exam weight | Grade with 100% on final | Grade with 70% on final | Grade with 0% on final |
|---|---|---|---|
| 10% | 86.5% | 83.5% | 76.5% |
| 20% | 88% | 82% | 68% |
| 25% | 88.75% | 81.25% | 63.75% |
| 30% | 89.5% | 80.5% | 59.5% |
| 40% | 91% | 79% | 51% |
| 50% | 92.5% | 77.5% | 42.5% |
With a light final, your grade is mostly decided already. With a final worth 40% or more, it can swing your grade by a whole letter or two in either direction.
The US letter-grade scale
The calculator uses this common US scale: A+ 97% and above, A 93–96, A− 90–92, B+ 87–89, B 83–86, B− 80–82, C+ 77–79, C 73–76, C− 70–72, D+ 67–69, D 63–66, D− 60–62, and F below 60%. Many schools and teachers use different cutoffs, such as a flat 90/80/70/60 with no pluses or minuses. Your syllabus always wins. To turn letter grades into a grade point average, use the GPA calculator.
Tips
- Use category averages, not single assignments. If homework is 20% of your grade, enter your overall homework percentage. If you only have raw scores, the average calculator or percentage calculator will get you there.
- Watch dropped scores and extra credit. If your teacher drops your lowest quiz, leave it out of your quiz average.
- Points-based classes don’t need weights. Divide total points earned by total points possible, or enter each category with its share of the total points as the weight.
- Plan early. Running this calculation before the final shows whether to put extra study time into this class or another one.
Assumptions
The calculator assumes your current grade is already weighted correctly and that the final exam is a single category added on top. It doesn’t round: an 89.99% is a B+. Scores above 100% are allowed for extra credit, up to 200%.
Frequently asked questions
How do I calculate a weighted grade?
Multiply each category's score by its weight, add the results, and divide by the total weight. With homework at 90% (worth 20%), quizzes at 85% (30%) and exams at 78% (50%), that's 18 + 25.5 + 39 = 82.5%. If your weights add up to 100%, the division step changes nothing.
What do I need on my final to get the grade I want?
Use (goal − current × (1 − w)) ÷ w, where w is the final's weight as a decimal. With an 84% going into a final worth 25% and a goal of 85%, you need (85 − 84 × 0.75) ÷ 0.25 = 88% on the final.
What if my weights don't add up to 100%?
That usually means some work hasn't been graded yet. The calculator divides by the weights you entered, which gives your grade on the work done so far. If your weights add to more than 100%, double-check your syllabus.
What is a B− in percentage?
On the common US scale, a B− is 80% up to 83%, a B is 83% up to 87%, and a B+ is 87% up to 90%. Each letter band is about 10 points wide, split roughly into thirds for minus, plain and plus. Your teacher's syllabus has the final word.
Why does the calculator say I need more than 100%?
Your goal is out of reach with the final alone. Even a perfect score wouldn't lift your grade that far. The results show the highest grade you can still reach, and the table shows which letter grades are still possible.
Does my teacher round grades up?
Some do and some don't. This calculator doesn't round, so 89.9% counts as a B+, not an A−. If your teacher rounds 89.5% up to 90%, you can set your goal half a point lower.
Updated November 2026. Results are estimates for educational purposes and depend on the inputs you provide.