Grade Calculator

The Grade Calculator computes a weighted final grade from a dynamic list of assignments, and it is honest about the mathematics that most students only guess at. Each row accepts an optional assignment name, a grade entered either as a percentage or as a letter, and a weight expressed as a percent of the course. The tool multiplies every valid grade by its weight, sums the products, and divides by the total weight of the rows you entered — so even if your weights do not sum to 100%, the final grade remains a correct weighted average rather than a distorted one. Letter grades map to fixed midpoints: A becomes 95, B becomes 85, C 75, D 65, and F 50, while the reverse conversion uses the classic cutoffs of 90, 80, 70, and 60. A live result panel shows the final percentage, its letter grade, and the total weight, with an amber warning when weights drift from 100%. Rows with invalid or non-positive weights are ignored in the calculation, and the tool says so.

1. 1

   Review the three starter rows (Homework, Midterm, Final) or delete them with the trash icon.

2. 2

   Click Add assignment to append a new row to the list.

3. 3

   For each row, choose Percent or Letter in the Grade type dropdown and fill in the grade and Weight (%) fields.

4. 4

   Watch the Final grade, Total weight, and Letter stats update live as you edit.

5. 5

   Check the amber badge if it appears — it warns when your weights do not sum to 100%.

• Calculating a mid-semester weighted average to see whether a B is still possible.
• Figuring out the minimum grade needed on a weighted final exam to hold an A.
• Handling mixed grading systems by entering some assignments as letters and others as percentages.
• Auditing a syllabus where the stated weights are missing or add up to less than 100%.
• Estimating a predicted grade before official results are released.
• Settling a dispute over a professor's grade math by replicating the weighted average.

• Copy weights straight from the syllabus — the live total-weight stat will immediately flag any typos or missing categories.
• Prefer percentage inputs for precision; letter inputs snap to fixed midpoints that can understate an 89.5% borderline A.
• Keep weights summing to 100% for interpretability, even though the calculator still computes correctly otherwise.
• Delete rows you are not tracking rather than entering zeros, since non-positive weights are ignored but add clutter.
• Note that results are not saved between sessions, so screenshot or write down the final figure before closing the tab.
• Treat the letter conversion cutoffs as generic: many courses use plus/minus scales, so read the final letter as an estimate.

• Enter the final exam as its own row and adjust the grade until your final flips from B to A.
• Use the trash icon to clear the starter rows before building your own list.
• Mix one letter row into an all-percentage list to model participation marks quickly.
• Watch the total weight badge — it is the fastest way to spot a missing syllabus category.