Grade Curve Calculator
Curve a whole class at once — paste a column of scores, pick a method, watch the before/after distribution update live.
Percent of max score. Below D is F. Applies to the curved score.
Or see it work on a worked example first.
Before
After
| Name | Original | Curved | Grade |
|---|
How this works & why it’s private
Everything runs in your browser as plain JavaScript — parsing, the curve math, the chart and the export are all done in memory on your device. Nothing you paste is ever sent anywhere; there is no server for it to go to. To verify, open your dev-tools Network tab and watch the uploads counter in the top bar stay at 0 no matter what you paste or export.
Flat / linear add adds the same number of points to every score. Scale highest to 100 multiplies every score by 100 / top score so the best paper in the class becomes a perfect score. Square-root curve uses the standard formula newScore = √(rawScore) × 10 (assumes scores are already out of 100). Normalize (bell curve) converts every score to a z-score against the class mean and standard deviation, then rescales it to whatever mean and SD you choose — the shape of the distribution is preserved, only its center and spread move.
Your last method, parameters and cutoffs are kept in this browser's localStorage so they’re still here next time — nothing is uploaded to keep them.