Grade Calculator
Add each assignment, exam, or category with its grade and weight to see your overall course percentage and letter grade — calculated instantly in your browser.
Frequently Asked Questions
How is a weighted grade calculated?
Each grade is multiplied by its weight, those products are added together, and the total is divided by the sum of the weights. So a 90 worth 40% and an 80 worth 60% give (90×40 + 80×60) ÷ 100 = 84%.
Do the weights need to total 100%?
No. The calculator normalizes by dividing by whatever the weights add up to, so the result is correct either way. It does warn you when the total is not exactly 100% in case you missed an assignment.
Does it show a letter grade?
Yes. Alongside the overall percentage it shows a letter grade using the standard scale — A for 90 and up, B for 80–89, C for 70–79, D for 60–69, and F below 60.
Understanding the Grade Calculator
The Grade Calculator works out your overall course grade when different assignments count for different amounts. Instead of a plain average, it uses a weighted average: a final exam worth 40% pulls your grade far more than a quiz worth 5%. Add a row for each assignment, exam, or category, enter the grade you earned as a percentage and how much it is worth, and the tool returns your overall percentage plus the matching letter grade. It also shows the total weight you have entered and flags it if those weights do not add up to 100%, so you can spot a missing item. Everything runs in your browser — nothing is uploaded.
How it works
Start with the four rows provided, or use "Add assignment" for more and the remove button to delete any you do not need. For each row, type the grade as a percentage (for example, 18 out of 20 is 90) and the weight that piece carries toward the final grade. The assignment name is optional and only labels your results. When you press "Calculate grade", the tool multiplies each grade by its weight, adds those products together, and divides by the sum of all the weights — so the answer is correct whether your weights total 100% or not. It then maps the percentage to a letter grade and shows the total weight used. Rows you leave blank are ignored.
Worked example
Imagine a class with three components: homework worth 20%, a midterm worth 30%, and a final exam worth 50%. You scored 95 on homework, 82 on the midterm, and 88 on the final. The tool computes 95×20 + 82×30 + 88×50 = 1900 + 2460 + 4400 = 8760, then divides by the total weight of 100, giving an overall grade of 87.6%. Because that falls in the 80–89 band, your letter grade is B. The total-weight readout confirms 100%, so no warning appears.
Tips & common mistakes
- Enter grades as percentages — if you have points earned and points possible, divide first (e.g. 45 ÷ 50 = 90).
- Weights do not have to total 100%; the tool normalizes them, but the warning helps you catch a category you forgot to add.
- Leave a row blank to keep a placeholder for an assignment you have not taken yet — empty rows are skipped in the math.
- Use it to find the score you still need: enter your known grades, then try different values in the remaining row until you hit your target overall percentage.
- Letter-grade cutoffs vary by school — this tool uses the common 90/80/70/60 scale, so check your syllabus if yours rounds differently or uses plus/minus grades.
- Copy the result or download the CSV before you reset, so you have a record of each assignment's contribution.