Grade Calculator
Calculate your weighted course grade. Enter each category's grade and weight to see your overall percentage and letter grade.
| Item | Grade % | Weight % | |
|---|---|---|---|
How to use this calculator
Add each graded component — homework, quizzes, midterms, the final exam — with its percentage grade and weight. Click + Add category for more rows. The calculator returns your overall percentage, the matching letter grade, and your total weight so you can verify it sums to 100%.
If you do not have a grade for a future assignment yet, simply leave it out and your result will reflect your standing on completed work only. You can also enter a hypothetical grade on a future exam to see what overall score it would produce — useful for figuring out what you need on the final.
How weighted grades work
Most courses do not treat every assignment equally. Your professor's syllabus assigns each category a weight — the percentage of your final grade that category controls. A typical breakdown might look like: homework 20%, quizzes 10%, midterm 30%, final exam 40%. That means the final exam has four times the influence on your grade as homework, and twice the influence of quizzes.
A simple (unweighted) average would treat all three equally, which is not how most professors grade. The weighted average accounts for each category's importance by scaling its grade proportionally before summing. This is why a strong performance on a heavily weighted final can rescue a shaky midterm, while an excellent homework average barely moves the needle if homework is only 10% of the grade.
Worked example: full semester
Consider a course with this grade structure:
- Homework: 91%, weight 20
- Quizzes: 78%, weight 15
- Midterm exam: 83%, weight 25
- Final exam: 89%, weight 40
Calculation: (91×20 + 78×15 + 83×25 + 89×40) ÷ (20+15+25+40)
= (1820 + 1170 + 2075 + 3560) ÷ 100
= 8625 ÷ 100
= 86.25% → B
Notice that the quiz average (78%) dragged things down, but because it carries only 15% weight, the damage is limited. The strong final exam (89%) at 40% weight is the single biggest contributor to the overall grade.
Worked example: what do I need on the final?
Suppose after homework, quizzes, and the midterm you have completed 60% of the grade weight and your current weighted score on those components is 82%. You want a B (83%) in the course. The final is worth 40%. What do you need?
Rearranging: Final score = (Target − Current weighted score × current weight share) ÷ remaining weight share
= (83 × 100 − 82 × 60) ÷ 40
= (8300 − 4920) ÷ 40
= 3380 ÷ 40
= 84.5% on the final
You can also do this interactively: enter your completed categories in the calculator, add a "Final" row at 40%, and adjust the final's grade until the overall result hits 83%.
How to interpret your result
The overall percentage is compared against a common letter-grade scale. The scale this calculator uses is typical for US colleges (A starts at 93%, B at 83%, etc.), but your specific school or professor may use different cutoffs. A professor who grades on a 90/80/70 scale would give you a B at 83% rather than the B- this calculator shows. Always verify with your syllabus.
If your weights do not add up to 100% — for instance, because a future assignment has not yet been graded — the percentage shown is your standing proportional to the completed work, not your projected final grade. Add the missing categories with estimated scores to project forward.
Common mistakes to avoid
- Simple-averaging grades instead of weighting them. If you add up your grades and divide by the number of assignments, you ignore the fact that some assignments count more. The result can be significantly off from your actual course grade.
- Entering points instead of percentages. This calculator expects a percentage (0–100) as the grade. If you scored 43/50, convert that to 86% before entering it.
- Forgetting to verify that weights total 100%. The calculator divides by whatever total weight you enter, so if your weights sum to 80 instead of 100, the result reflects an incomplete picture. The total weight display helps you catch this.
- Assuming this matches your official grade exactly. Rounding methods differ. Some professors round each category score to the nearest whole point before weighting; others carry full decimal precision through the calculation. A fraction of a point discrepancy is normal and your professor's grade is the official one.
- Overlooking extra credit. If your syllabus offers extra credit, add it as a separate row. The overall percentage may exceed 100%, which is fine — it reflects the bonus points.
The formula
Overall % = Σ(grade × weight) ÷ Σ(weight)
What you need on the final = (Target overall × total weight − current weighted sum) ÷ final weight
How we calculate this
The overall grade is calculated as the sum of (each category's percentage score × its weight) divided by the sum of all weights. Letter grades are assigned using a common US percentage scale; exact cutoffs vary by institution — always check your syllabus.
Frequently asked questions
How do I calculate my weighted course grade?
Multiply each graded category's percentage score by its weight, sum those products, then divide by the total weight. For example: homework 88% (weight 20) + midterm 82% (weight 30) + final 90% (weight 50) = (88×20 + 82×30 + 90×50) ÷ 100 = 87.2%.
Do all my weights need to add up to 100%?
Ideally yes — if your weights sum to 100, the result is your true course grade. But the calculator divides by the total weight you enter, so you can enter a partial syllabus (e.g., weights totaling 70 mid-semester) and still see a meaningful proportional score for the work completed so far.
How is the letter grade determined from a percentage?
This calculator uses a common US college scale: 93–100 = A, 90–92 = A-, 87–89 = B+, 83–86 = B, 80–82 = B-, 77–79 = C+, 73–76 = C, 70–72 = C-, 67–69 = D+, 63–66 = D, 60–62 = D-, below 60 = F. Your school's specific cutoffs may differ — check your syllabus.
How do I figure out what I need to earn on my final exam?
Enter all the categories you have already completed with their actual grades and weights, then add the final exam as a new row with its weight and try different grade values until the overall result hits your target. For example, if you have an 85% on 60% of the course weight and want a 90% final grade, you need roughly a 97.5% on the final to get there.
Can I use this for extra-credit categories?
Yes — just add the extra-credit component as a row with its weight. If extra credit adds 5 points to a course graded out of 100, you can model it as a category worth 5 weight points with whatever score you earned. The total weight will exceed 100, and the resulting percentage may rise above 100%.
What if some of my grades are entered as points, not percentages?
Convert them first: divide the points earned by the points possible and multiply by 100. If you scored 43 out of 50 on a quiz, that is 43 ÷ 50 × 100 = 86%. Enter 86 as the grade for that row.
Why is my grade different from what the professor posted?
Differences usually come from rounding, how incomplete or dropped scores are handled, or a slightly different letter-grade scale. Some professors round each category grade before weighting; others weight raw points and round once at the end. If your computed grade differs from your official grade, the professor's calculation method and grading scale take precedence.
Can I use this calculator for a high school class?
Yes. The weighted-average math is the same regardless of school level. The letter-grade scale this calculator uses (A starts at 93%) is common but not universal — some high schools use 90% as the A threshold, and a few use 94% or 95%. Check your school's grading policy to verify the cutoffs.