About the Grade Calculator
This free Grade Calculator works out your weighted class grade and matching letter grade in seconds. Enter the score you got on each assignment, quiz, or test along with how much it's worth (its weight), and your overall percentage updates live. Empty rows are ignored, so you can use anywhere from two to six categories.
It uses the standard US grading scale (A, B, C, D, F), and shows whether your weights add up to 100% so your result stays accurate. Your marks are calculated in the browser as you type. Nothing is uploaded, so there is no record anywhere of a grade you might rather keep to yourself.
How to use it
- Add each assessment with its weight and the score you received.
- Make sure the weights total 100%.
- Read your overall weighted grade.
Why weights change everything
A course grade is almost never the plain average of your scores. Each component carries a weight, and a 30%-weighted final counts three times as heavily as a 10%-weighted quiz.
The arithmetic: multiply each score by its weight, then add the products. If the weights sum to 100%, the total is your grade.
A worked example
Four components:
- Homework, 20% weight, scored 88 → 17.6
- Midterm, 30% weight, scored 76 → 22.8
- Project, 20% weight, scored 92 → 18.4
- Final, 30% weight, scored 81 → 24.3
Total: 83.1%.
A plain average of 88, 76, 92 and 81 would give 84.25. The weighted figure is lower because the weakest score sits in one of the heaviest components — which is exactly the information a plain average hides.
Common mistakes
- Weights that do not total 100%, which silently distorts the result.
- Entering points earned instead of a percentage score for each component.
- Overlooking a dropped-lowest-grade policy, which changes the calculation entirely.
Questions people ask
What if my weights don't add to 100%?
Either you have missed a component or an assessment has not happened yet. For a grade so far, divide your weighted total by the weights actually used.
How do I work out what I need on the final?
Use the Final Grade Calculator, which solves the equation the other way round.
Can I use points instead of percentages?
Convert each component to a percentage first, then apply its weight.