Grade Curve Calculator
Apply flat, top-score or square-root curves to a raw score instantly.
Enter your values
Enter the raw score in %.
Choose one of: Flat curve — add points, Top score becomes 100, Square-root curve.
Enter the points to add (flat curve) you are working with.
Enter the highest score in class (top-score curve) you are working with.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Curved score
- 77 %
- Letter grade
- C+
- Points gained
- 5
Working
- 172 + 5 = 77
- 2Capped at 100 and mapped to a letter grade: C+
Quick answer
A grade curve adjusts raw scores upward. The three common methods are a flat curve (add n points), a top-score curve (scale so the highest score becomes 100) and a square-root curve (√score × 10).
Flat: raw + n · Top score: raw × 100 / highest · Square root: √raw × 10
At a glance
| What it does | Apply flat, top-score or square-root curves to a raw score instantly. |
|---|---|
| Category | Education |
| Inputs needed | Raw score, Curve method, Points to add (flat curve), Highest score in class (top-score curve) |
| Main output | Curved score |
| Formula | Flat: raw + n · Top score: raw × 100 / highest · Square root: √raw × 10 |
| Cost | Free — no sign-up, no download |
How to use the Grade Curve Calculator
- 1Enter the raw score.
- 2Choose the curve your instructor uses.
- 3Read the curved percentage and letter grade.
Inputs explained
- Raw score(%)
- Enter the raw score in %.
- Curve method
- Choose one of: Flat curve — add points, Top score becomes 100, Square-root curve.
- Points to add (flat curve)
- Enter the points to add (flat curve) you are working with.
- Highest score in class (top-score curve)
- Enter the highest score in class (top-score curve) you are working with.
Worked example
Using the values the calculator loads with:
Inputs
- Raw score72 %
- Curve methodFlat curve — add points
- Points to add (flat curve)5
- Highest score in class (top-score curve)88
Results
- Curved score77 %
- Letter gradeC+
- Points gained5
- 72 + 5 = 77
- Capped at 100 and mapped to a letter grade: C+
Frequently asked questions
What is a square-root curve?
Take the square root of the raw percentage and multiply by 10. A 64 becomes 80, a 49 becomes 70. Low scores gain the most and a 100 stays 100.
Is curving grades fair?
A flat or square-root curve raises everyone, so relative rank is unchanged. A strict bell curve, where a fixed share must receive each grade, can lower grades and is more controversial.
What do I need to enter into the Grade Curve Calculator?
Just 4 values: raw score, curve method, points to add (flat curve), highest score in class (top-score curve). Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Grade Curve Calculator work out the answer?
A grade curve adjusts raw scores upward. The three common methods are a flat curve (add n points), a top-score curve (scale so the highest score becomes 100) and a square-root curve (√score × 10). It applies the formula Flat: raw + n · Top score: raw × 100 / highest · Square root: √raw × 10 and shows the working so you can check each step by hand.
Is the Grade Curve Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.