How this calculator works
A test score answers a simple question: how much of the available credit did you earn? Divide your earned points by the total possible points and multiply by 100. You can enter fractional points, so 8.5 out of 10 is just as valid as 85 out of 100.
The percentage is mathematical; the letter grade is a school policy. This calculator starts with an example A/B/C/D scale of 90/80/70/60, but you can change each boundary. It compares the full-precision score, not a rounded display value. An 89.99% does not silently become an A. Extra credit above the total is allowed and can produce more than 100%.
Worked example: 42 points out of 50
- Divide 42 by 50 to get 0.84.
- Multiply by 100: your score is 84%.
- On the example scale, 84% is at least 80% but below 90%, so the estimated letter is B.
42 out of 50 = 84%, an estimated B on the example scale.
Example letter-grade boundaries
| Letter | Unrounded score |
|---|---|
| A | 90% and above |
| B | 80% to below 90% |
| C | 70% to below 80% |
| D | 60% to below 70% |
| F | Below 60% |
A test score is not always your course grade
Do not average test percentages when tests have different weights. A final exam worth 40% of the course counts differently from a quiz worth 5%. Use your course syllabus and the weighted-grades guide for that question.
Questions people ask
- Is this an official grade?
- No. The percentage follows your points, while the letter follows the thresholds you enter. Your teacher may use different boundaries, rounding or extra-credit rules.
- Can I enter partial points?
- Yes. For example, 8.5 points out of 10 is 85%. Both earned and possible points can have decimals.
- What happens with extra credit?
- Earned points can exceed possible points. 55 out of 50 is 110%. Whether a school caps that score is a policy decision this calculator does not impose.