Grade Curve Calculator
Paste a set of test scores and apply a curve — add points, set the top score to 100, scale, square-root curve, or shift to a target average — and see the curved scores, new letter grades and the grade distribution before and after.
How to Use
- Paste your class scores — one per line, or comma-separated. They're read as percentages (0–100).
- Choose a <strong>curve method</strong>: add a flat number of points, set the highest score to 100, scale everything up proportionally, apply a square-root curve, or shift the whole class to a target average.
- The tool shows each original score next to its curved value and new letter grade, the class average before and after, and the A–F distribution as a bar — so you can see exactly what the curve does before committing to it.
- All curved scores are capped at 100%.
Curve methods
About the Grade Curve Calculator
The Grade Curve Calculator gives you a fast, free answer for grading, GPA and study planning without sending anything off your device. Paste a set of test scores and apply a curve — add points, set the top score to 100, scale, square-root curve, or shift to a target average — and see the curved scores, new letter grades and the grade distribution before and after.
How it works
Enter your figures and the result appears instantly, updating the moment you change anything. There is no submit button and nothing to wait for, so it is easy to try a few what-if numbers and compare the results. Just check each box holds the kind of value it expects.
Want the deeper story? The Knowledge Base explains the ideas behind the tools in more detail.
Frequently Asked Questions
What do the different curve methods do?
<strong>Add points</strong> gives everyone the same flat boost. <strong>Highest = 100</strong> finds the top score and adds the gap to 100 to every student (a flat shift). <strong>Scale to 100</strong> multiplies every score so the top becomes 100 (helps lower scores more). <strong>Square-root</strong> curve replaces each score with √score × 10 — a gentle boost that helps low scores most and barely moves high ones. <strong>Target average</strong> shifts the whole class so the mean lands on the number you pick.
Which curve is fairest?
It depends on your goal. A flat “add points” keeps the spread between students identical. The square-root curve compresses the spread and rescues low scores — common when a test was too hard. Scaling to 100 rewards the relative ranking. There's no universally “fair” curve, so the tool shows the before/after distribution to help you decide.
Are scores capped at 100?
Yes — any curved value above 100 is capped at 100, so a near-perfect score plus a curve can't exceed full marks. (If your grading allows extra credit above 100, treat the cap as a guide.)
What letter grades does it use?
The standard 10-point scale: 90+ = A, 80–89 = B, 70–79 = C, 60–69 = D, below 60 = F, applied to the curved score. Adjust mentally if your school uses different cut-offs.
How do I use the Grade Curve Calculator?
Simply type your numbers and read the result, which refreshes the instant you change something. There is nothing to submit and nothing to wait for.
Does it cost anything or need an account?
No. The tool is completely free, there is no account to create, and it keeps working offline after the page first loads.
Is anything I type uploaded?
No. The tool works entirely on your device, so the values you enter never leave your browser.
Common Use Cases
Teachers
Try a curve on a hard test and see the new distribution before applying it.
Professors / TAs
Scale exam scores or shift to a target average across a section.
Comparing methods
See flat vs square-root vs scaling side by side on your real data.
Students
Estimate how a class curve might change your grade.
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