Convert a raw score into a curved percentage using the square-root method. Enter a grade (0–100) to get the curved percent, letter grade, step-by-step solution and interpretation.

The calculator computes the square root of the entered grade, multiplies it by 10, and shows the curved percentage, the corresponding letter grade, and a short, step-by-step solution so students and instructors can quickly verify results.

How to use it

1. Enter your original grade (between 0 and 100) in the input box.
2. Press Calculate Curved Grade or hit Enter.
3. Read the results: the curved percentage, the inferred letter grade, and the step-by-step math that produced the number.

Formula & math

Curved Grade = √Original Grade​× 10

Explanation: take the square root of the raw percent (e.g., √81 = 9), then multiply that value by 10 to convert it back to a percentage scale (9 × 10 = 90%). This method compresses extremes and raises lower scores more than top scores, producing a gentler curve than linear scaling.

Example

Input: Original Grade = 64

1. √64 = 8.00
2. 8.00 × 10 = 80.00% (curved grade)
3. Letter grade: B (based on the site’s letter thresholds: A ≥90, B ≥80, etc.)

A second quick example: original 81 → √81 = 9 → curved = 90 → A.

FAQ

Q1. Why does this curve use a square root?

A: The square root slows growth near the top of the scale and boosts lower scores, producing a more equitable spread across the grade distribution relative to linear scaling.

Q2. Is the curved grade the final grade I should report?

A: Not necessarily, many instructors combine curves with other policy rules (e.g., attendance, extra credit). Treat this result as a mathematically consistent conversion, not final course policy.

Q3. What happens if I enter 100?

A: √100 = 10 → 10 × 10 = 100. The formula leaves a perfect score perfect.

Q4. How precise is the answer?

A: The calculator shows results rounded to two decimal places and displays the intermediate square root for verification (matching classroom practice).