Grade curve calculator
Paste the class's scores, pick how to curve them and see every score before and after, with the new class average and letter grades.
Every score went up 8 points. 16 students.
Every score, before and after
| Student | Score | Before | Grade | After | Grade | Change |
|---|---|---|---|---|---|---|
| 1 | 58 | 58% | F | 66% | D | +8 |
| 2 | 62 | 62% | D− | 70% | C− | +8 |
| 3 | 65 | 65% | D | 73% | C | +8 |
| 4 | 67 | 67% | D+ | 75% | C | +8 |
| 5 | 70 | 70% | C− | 78% | C+ | +8 |
| 6 | 71 | 71% | C− | 79% | C+ | +8 |
| 7 | 73 | 73% | C | 81% | B− | +8 |
| 8 | 74 | 74% | C | 82% | B− | +8 |
| 9 | 76 | 76% | C | 84% | B | +8 |
| 10 | 78 | 78% | C+ | 86% | B | +8 |
| 11 | 79 | 79% | C+ | 87% | B+ | +8 |
| 12 | 81 | 81% | B− | 89% | B+ | +8 |
| 13 | 83 | 83% | B | 91% | A− | +8 |
| 14 | 85 | 85% | B | 93% | A | +8 |
| 15 | 88 | 88% | B+ | 96% | A | +8 |
| 16 | 92 | 92% | A− | 100% | A+ | +8 |
Four ways to curve grades
Top score becomes 100%
Find the highest score and add the points it was missing to everyone. If the top score is 92, every student gets 8 points. Simple and easy to explain to a class.
Add points to everyone
A flat bonus, like 5 points, for every student. Use it when you know a question was unfair or the test ran long.
Square root curve
The new score is 10 × √(score). An 81 becomes 90, a 64 becomes 80 and a 49 becomes 70. Lower scores get the biggest boost and a 100 stays 100.
Reach a class average
Pick the average you want, say 80%, and every student gets the same smallest bonus that brings the class there. With "No score above 100%" on, the bonus is a bit bigger to make up for scores that hit the cap.
Questions
What does curving a grade mean?
Curving raises scores after a test when the results came out lower than intended. Most teachers who curve add points, raise the top score to 100 or use a square root curve. Grading strictly on a bell curve, where a set share of students gets each letter, is much rarer in schools.
Which curve is the fairest?
Adding the same points to everyone keeps the gaps between students the same. A square root curve helps lower scores the most. The best one depends on why the test came out low.
Can a curve lower my grade?
None of the methods here lower a score. A target average below the current average leaves every score as it is.
Do the scores leave my browser?
No. The curve is calculated in your browser and the scores aren't sent anywhere, so it's fine to paste a real class list of scores (leave the names out).