Grade Curve Calculator
Apply flat, top-score or square-root curves to a raw score instantly.
Enter your values
Results update instantly as you type — no submit needed.
Results
- 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
How to use the Grade Curve Calculator
- 1Enter the raw score.
- 2Choose the curve your instructor uses.
- 3Read the curved percentage and letter grade.
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.