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Grade Curve Calculator

Enter a list of test scores and choose a curving method - scaling so the highest score becomes the target maximum, or adding a flat number of points to every score - to see each student’s curved result. Useful for teachers reviewing grade distributions.

  • Nothing leaves your device
  • Runs entirely in your browser
  • Free, no account needed
Use Grade Curve Calculator - free

How this works in your browser

Both methods are additive shifts rather than redistributions. Scaling to the top score computes the gap between the highest score and your target maximum and adds that same amount to every score; the flat method adds a number you choose. Because each adds a constant, the gaps between students are preserved exactly, so the ranking and the spread are unchanged and only the overall level moves. Results are capped at the maximum, which is the one place the transformation stops being uniform. This is deliberately different from curving to a fixed distribution, which forces a predetermined proportion into each grade regardless of how the class actually performed.

Grade Curve Calculator vs. typical online calculators

FeatureGrade Curve Calculator (in-browser)Typical online calculators
Where the maths runsIn your browser, on your deviceOften posted to a server to compute
Your inputs are storedNever - nothing is sent or savedFrequently logged with your session
Works offline once loadedYesNo - needs a live connection
Ads inside the result areaNoneCommon on free calculators
Account requiredNoOften, to save or export results
Usage limitsNone - free, unlimited useSometimes capped per day

Who uses Grade Curve Calculator

Adjusting for a hard test

Lift a whole class when an assessment proved harder than intended.

Compensating for a flawed question

Add points for a question that was ambiguous or unfair.

Reviewing a distribution

See how a proposed adjustment would change the spread before committing.

Comparing curving options

Try both methods on the same scores to see which produces a fairer result.

How to use Grade Curve Calculator

  1. 1

    Open the Grade Curve Calculator

    Go to tools.slaytic.com and open the Grade Curve Calculator. No sign-up or account required.

  2. 2

    Paste your scores

    Separate them with commas, spaces or new lines in any combination.

  3. 3

    Choose a curving method

    Scale so the top score reaches your target, or add a flat number of points.

  4. 4

    Review the curved results

    Check the distribution before applying it to your gradebook.

Frequently asked questions

What curving methods are available?

"Curve so the highest = target" shifts every score up by the same amount so the top score reaches your target maximum. "Add a flat number of points" simply adds a fixed number of points to every score.

Can curved scores exceed the target maximum?

No, curved scores are capped at the target maximum you set, so no student can score above it after curving.

How do I enter scores?

Separate scores with commas, spaces, or new lines - any combination works.

Which curving method should I use?

Scaling to the top score suits a test that was harder than intended, since it lifts everyone by the same amount the best student fell short by. A flat addition suits a specific known problem, such as an ambiguous question worth five marks. Both preserve the ranking; neither changes who did better than whom.

Does curving actually help students?

These methods do, because both raise every score. What does not is curving to a fixed distribution, where a set proportion must receive each grade regardless of performance. That approach turns a class into competitors rather than a cohort, and it is worth distinguishing from the additive methods here.

Why are curved scores capped at the maximum?

Because a score above the maximum is not meaningful on most grading systems and creates problems downstream in gradebooks and transcripts. Capping means students already near the top gain less, which is an unavoidable consequence of having a ceiling at all.

Are my students' scores transmitted anywhere?

No. The calculation runs in your browser, so a class's marks are never uploaded, which matters given student grades are protected data in most jurisdictions.

Curve grades instantly - free.

Open Grade Curve Calculator
  • Nothing leaves your device
  • No upload required
  • No account needed
  • Unlimited use, always free