Teacher Grading Calculator
Enter student scores and a grading scale to assign letter grades, see class distribution, and optionally apply a curve.
Built for teachers.
Teacher grading calculations involve two main operations: computing a student’s weighted total score, and converting raw scores to letter grades using a defined grade scale.
Weighted Average Formula:
Final Grade = Sum of (Score × Weight) for each category
All weights must sum to 100% (or 1.0 in decimal form).
Worked example:
| Category | Weight | Student Score |
|---|---|---|
| Tests | 40% | 78% |
| Homework | 25% | 92% |
| Projects | 20% | 85% |
| Participation | 15% | 100% |
Final Grade = (78 × 0.40) + (92 × 0.25) + (85 × 0.20) + (100 × 0.15) = 31.2 + 23.0 + 17.0 + 15.0 = 86.2% → B
Standard letter grade scale (most US schools):
| Score Range | Letter Grade | GPA Points |
|---|---|---|
| 90–100% | A | 4.0 |
| 80–89% | B | 3.0 |
| 70–79% | C | 2.0 |
| 60–69% | D | 1.0 |
| Below 60% | F | 0.0 |
Points-based grading (alternative): When assignments are worth different point totals: Percentage = Total Points Earned / Total Points Possible × 100 Example: 342 earned / 400 possible = 85.5% → B
The two curves this calculator offers:
- Curve to 100: work out the gap between the highest score in the class and 100, then add that many points to everyone. This is a flat curve anchored at the top score. It lifts every student by the same amount and leaves the gaps between them untouched, so a 40 stays exactly 30 points behind a 70.
- Square root curve: new score = √raw × 10. This compresses the scale and helps weaker students far more than strong ones. A 49 becomes 70; a 90 becomes about 95.
A third approach you will see described elsewhere, sometimes confusingly under the same “curve to 100” name, is the multiplicative top-score curve: divide every score by the class maximum and multiply by 100. That one scales the gaps as well as the scores, so it treats the best work in the room as the definition of full marks. It is not offered here; the Grade Curve Calculator implements all three side by side if you want to compare them on the same class.
Curving should be applied consistently and announced to students in advance to maintain trust and fairness.
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.